Systems for PET imaging

ABSTRACT

The present disclosure relates to a system for PET imaging. The system may include a first device and a second device. The first device may include a first scanning channel. The second device may include a second scanning channel connected to the first scanning channel, a heat generating component, and a cooling assembly configured to cool the heat generating component, wherein the cooling assembly may include an inlet chamber and a return chamber, the heat generating component may be closer to a first side of the second device than at least one of the inlet chamber or the return chamber, and the first side of the second device may face the first device.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a division of U.S. patent application U.S.15/721,776, filed on Sep. 30, 2017, which claims priority of ChinesePatent Application No. 201610874155.7 filed on Sep. 30, 2016, ChinesePatent Application No. 201610899032.9 filed on Oct. 14, 2016, ChineseApplication No. 201621125553.0 filed on Oct. 14, 2016, ChineseApplication No. 201611032775.2 filed on Nov. 15, 2016, ChineseApplication No. 201621280709.2 filed on Nov. 25, 2016, ChineseApplication No. 201611086609.0 filed on Nov. 30, 2016, and ChinesePatent Application No. 201611256679.6 filed on Dec. 30, 2016, the entirecontents of each of which are hereby incorporated by reference.

TECHNICAL FIELD

This present disclosure relates to an imaging system, and moreparticularly, relates to a positron emission tomography (PET) imagingsystem and a positron emission tomography-computed tomography (PET-CT)imaging system.

BACKGROUND

Positron emission computed tomography (PET) is a nuclear medicinefunctional imaging technique that is used to observe metabolicactivities in a subject. A PET system has multiple components includinga gantry assembly, a detector assembly, a cooling assembly, etc. Properinstallation, maintenance, and protection of the multiple components mayaffect various aspects of performance of a PET system including, e.g.,the imaging accuracy, service life, work efficiency, etc. It isdesirable to improve the design of multiple components to facilitate theinstallation, maintenance, and protection of the PET system. Besides, asubject needs to be exposed to radiation in PET-CT imaging. Thus, it isdesirable to improve the design of the PET-CT imaging system to reducethe radiation dose.

SUMMARY

One aspect of the present disclosure relates to a system for imaging.The system may include a first device and a second device. The firstdevice may include a first scanning channel. The second device mayinclude a second scanning channel connected to the first scanningchannel, a heat generating component, and a cooling assembly configuredto cool the heat generating component, wherein the cooling assembly mayinclude an inlet chamber and a return chamber, the heat generatingcomponent may be closer to a first side of the second device than atleast one of the inlet chamber or the return chamber, and the first sideof the second device may face the first device.

Another aspect of the present disclosure relates to a system forimaging. The system may include a detector assembly, a gantry assembly,and a cooling assembly. The detector assembly may include a plurality ofdetector modules. The gantry assembly may include a main gantry and agantry base, wherein the gantry base may be configured to support themain gantry, and the detector assembly may be mounted on the maingantry. The cooling assembly may include a cooler, a chilling chambersurrounding the plurality of detector modules, an inlet chamber, and areturn chamber, wherein the inlet chamber may be in fluid communicationwith the chilling chamber, the return chamber may be in fluid connectionwith the cooler, the inlet chamber and the return chamber may have acommon plane, and the common plane may include a first thermalinsulation layer.

A further aspect of the present disclosure relates to a system forimaging. The system may include a gantry assembly, a heat generatingcomponent mounted on the main gantry, a cooling assembly, and a slidingdevice. The gantry assembly may include a main gantry and a gantry baseconfigured to support the main gantry. The cooling assembly may beconfigured to cool the heat generating component. The sliding device maybe configured underneath the cooling assembly to facilitate mounting ofthe cooling assembly.

A further aspect of the present disclosure relates to a system forimaging. The system may include a detector assembly and a gantryassembly. The detector assembly may include a plurality of detectormodules and a detector support configured to support the plurality ofdetector modules, wherein the detector support may have a plurality ofguide units, and the plurality of guide units may be configured tofacilitate mounting of the plurality of detector modules and limitmovement of the plurality of detector modules. The gantry assembly mayinclude a main gantry, a back cover plate, and a gantry base configuredto support the main gantry, wherein a portion of the main gantry mayform a front face of a scanning channel, a portion of the back coverplate may form a back face of the scanning channel, a portion of thedetector assembly may form a sidewall of the scanning channel, and thedetector assembly may be mounted on the main gantry and the back coverplate.

A further aspect of the present disclosure relates to a system for PETimaging. The PET system may include a scanning channel with a front faceand a back face, a detector assembly including a plurality of detectormodules surrounding the scanning channel, a first ring, and a secondring. The first ring may be configured on a first side of the detectorassembly facing the front face of the scanning channel. The second ringmay be configured on a second side of the detector assembly facing theback face of the scanning channel, wherein at least one of the firstring or the second ring may include at least two segments.

Additional features will be set forth in part in the description whichfollows, and in part will become apparent to those skilled in the artupon examination of the following and the accompanying drawings or maybe learned by production or operation of the examples. The features ofthe present disclosure may be realized and attained by practice or useof various aspects of the methodologies, instrumentalities, andcombinations set forth in the detailed examples discussed below.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure is further described in terms of exemplaryembodiments. These exemplary embodiments are described in detail withreference to the drawings. These embodiments are non-limiting exemplaryembodiments, in which like reference numerals represent similarstructures throughout the several views of the drawings, and wherein:

FIG. 1 is a block diagram illustrating an exemplary imaging systemaccording to some embodiments of the present disclosure;

FIG. 2 is a block diagram illustrating an exemplary gantry assemblyaccording to some embodiments of the present disclosure;

FIG. 3 is a block diagram illustrating an exemplary detector assemblyaccording to some embodiments of the present disclosure;

FIG. 4 is a block diagram illustrating an exemplary cooling assemblyaccording to some embodiments of the present disclosure;

FIGS. 5A and 5B illustrate structural components of an exemplary scanneraccording to some embodiments of the present disclosure;

FIG. 6A illustrates a front view of an exemplary scanner according tosome embodiments of the present disclosure;

FIG. 6B illustrates a front view of an exemplary scanner according tosome embodiments of the present disclosure;

FIG. 6C is a schematic diagram illustrating an exemplary scanneraccording to some embodiments of the present disclosure;

FIG. 6D is a schematic diagram illustrating an exemplary scanneraccording to some embodiments of the present disclosure;

FIGS. 7A and 7B illustrate side views of exemplary scanners according tosome embodiments of the present disclosure;

FIGS. 8A through 8C illustrate three views of an exemplary scannerincluding a position adjustment device according to some embodiments ofthe present disclosure;

FIG. 9A illustrates an exemplary position adjustment device according tosome embodiments of the present disclosure;

FIG. 9B illustrates a side view of an exemplary position adjustmentdevice according to some embodiments of the present disclosure;

FIG. 9C illustrates a bottom view of an exemplary position adjustmentdevice according to some embodiments of the present disclosure;

FIG. 9D illustrates a sectional view taken along E-E′ of FIG. 9Caccording to some embodiments of the present disclosure;

FIG. 10 illustrates an exemplary fixed pin according to some embodimentsof the present disclosure;

FIG. 11A illustrates an exemplary position adjustment device accordingto some embodiments of the present disclosure;

FIG. 11B illustrates an exemplary position adjustment device accordingto some embodiments of the present disclosure;

FIG. 12A illustrates an exemplary detector cover according to someembodiments of the present disclosure;

FIG. 12B illustrates an exemplary detector cover according to someembodiments of the present disclosure;

FIG. 12C illustrates a top view of the detector cover shown in FIG. 12Aaccording to some embodiments of the present disclosure;

FIG. 12D illustrates a sectional view from L-L′ of FIG. 12C according tosome embodiments of the present disclosure;

FIG. 13A illustrates an enlarged view of the region A shown in FIG. 12Daccording to some embodiments of the present disclosure;

FIG. 13B illustrates an enlarged view of the region B shown in FIG. 12Daccording to some embodiments of the present disclosure;

FIG. 14 illustrates a schematic front view of an exemplary scanner witha detector cover according to some embodiments of the presentdisclosure;

FIG. 15 illustrates an exemplary ring assembly according to someembodiments of the present disclosure;

FIG. 16 illustrates a schematic configuration of an exemplary scannerwith a ring according to some embodiments of the present disclosure;

FIG. 17A illustrates an enlarged view of the region B shown in FIG. 6Aaccording to some embodiments of the present disclosure;

FIG. 17B illustrates an exemplary detector module and an exemplary guideplate according to some embodiments of the present disclosure;

FIG. 18A illustrates an exemplary detector module and an exemplary guideunit according to some embodiments of the present disclosure;

FIG. 18B illustrates an exemplary detector module and an exemplary guideunit according to some embodiments of the present disclosure;

FIG. 18C illustrates an exemplary detector module and an exemplary guideunit according to some embodiments of the present disclosure;

FIG. 19A illustrates a perspective view of an exemplary gantry and anexemplary sliding device of an imaging device (e.g., a PET device)according to some embodiments of the present disclosure;

FIG. 19B illustrates a perspective view of an exemplary sliding deviceaccording to some embodiments of the present disclosure;

FIG. 19C illustrates a front view of an exemplary sliding deviceaccording to some embodiments of the present disclosure;

FIG. 19D illustrates a side view of an exemplary sliding deviceaccording to some embodiments of the present disclosure;

FIG. 19E illustrates a top view of an exemplary sliding device accordingto some embodiments of the present disclosure;

FIGS. 20A and 20B illustrates a perspective view and a front view ofanother exemplary sliding device according to some embodiments of thepresent disclosure;

FIG. 21 illustrates a perspective view of an exemplary cooling devicesupported on an exemplary sliding device according to some embodimentsof the present disclosure;

FIG. 22A illustrates a schematic diagram of an exemplary coolingassembly installed in an exemplary gantry according to some embodimentsof the present disclosure;

FIG. 22B illustrates a schematic diagram of an exemplary coolingassembly installed in an exemplary main mounting plate according to someembodiments of the present disclosure;

FIG. 23A illustrates an exemplary cooling device according to someembodiments of the present disclosure;

FIG. 23B illustrates an internal structure of the exemplary coolingdevice shown in FIG. 23A according to some embodiments of the presentdisclosure;

FIG. 24A illustrates an exemplary PET-CT imaging device according tosome embodiments of the present disclosure; and

FIG. 24B illustrates an exemplary PET-CT imaging device according tosome embodiments of the present disclosure.

DETAILED DESCRIPTION

In the following detailed description, numerous specific details are setforth by way of examples in order to provide a thorough understanding ofthe relevant disclosure. However, it should be apparent to those skilledin the art that the present disclosure may be practiced without suchdetails. In other instances, well known methods, procedures, systems,components, and/or circuitry include been described at a relativelyhigh-level, without detail, in order to avoid unnecessarily obscuringaspects of the present disclosure. Various modifications to thedisclosed embodiments will be readily apparent to those skilled in theart, and the general principles defined herein may be applied to otherembodiments and applications without departing from the spirit and scopeof the present disclosure. Thus, the present disclosure is not limitedto the embodiments shown, but to be accorded the widest scope consistentwith the claims.

It will be understood that the term “system,” “unit,” “module,” and/or“block” used herein are one method to distinguish different components,elements, parts, section or assembly of different level in ascendingorder. However, the terms may be displaced by other expression if theymay achieve the same purpose.

It will be further understood that the terms “cover,” “plate,” “base,”“piece,” “rail,” “hole,” “ring,” “component,” “assembly,” “layer,” etc.,when used in this disclosure, refer to one or more parts with one ormore specific purposes. However, a structure that may perform a same orsimilar function compared to a part exemplified above or referred toelsewhere in the present disclosure may be named differently from thepresent disclosure.

It will be understood that when a unit, engine, module or block isreferred to as being “on,” “connected to” or “coupled to” another unit,engine, module, or block, it may be directly on, connected or coupledto, or communicate with the other unit, engine, module, or block, or anintervening unit, engine, module, or block may be present, unless thecontext clearly indicates otherwise. As used herein, the term “and/or”includes any and all combinations of one or more of the associatedlisted items.

The terminology used herein is for the purposes of describing particularexamples and embodiments only, and is not intended to be limiting. Asused herein, the singular forms “a,” “an,” and “the” may be intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “include,”and/or “comprise,” when used in this disclosure, specify the presence ofintegers, devices, behaviors, stated features, steps, elements,operations, and/or components, but do not exclude the presence oraddition of one or more other integers, devices, behaviors, features,steps, elements, operations, components, and/or groups thereof.

Provided herein are systems and components for non-invasive biomedicalimaging, such as for disease diagnostic or research purposes. The systemmay include a single imaging modality or multiple imaging modalities forconducting different medical scans or studies, including but not limitedto ultrasound scan, X-ray scan, bone densitometry, fluoroscopy, computedtomography (CT), digital radiography (DR), single photon emissioncomputed tomography (SPECT), magnetic resonance imaging (MRI), positronemission tomography (PET), or the like, or any combination thereof.

The term “imaging modality” or “modality” as used herein broadly refersto an imaging method or technology that gathers, generates, processesand/or analyzes imaging information of a target body through aparticular mechanism. The term “target body” or “object” as used hereinbroadly relates to any organic or inorganic mass, natural or man-made tobe imaged or examined. Exemplary embodiments of a target body pertainingto the present disclosure include cells, tissues, organs or whole bodiesof human or animal. Other exemplary embodiments of a target body includebut not limited to a man-made composition of organic and/or inorganicmatters that are with or without life.

Accordingly, a multi-modality imaging system of the present disclosurecan include more than one imaging modality, such as two, three, or moredifferent modalities. In a multi-modality system, the mechanisms throughwhich different imaging modalities operate or function may be the sameor different. Accordingly, the imaging information may also be the sameor different. For example, in some embodiments, the imaging informationmay be internal and/or external information, functional and/orstructural information of the target body, or the like, or a combinationthereof. In some embodiments, the imaging information of differentmodalities may complement one another, thereby providing a set ofimaging data describing a target body. For example, in some embodiments,the multi-modality imaging may achieve the merging of morphological andfunctional images.

The above types of imaging modalities that may be included in thepresent system are not exhaustive and are not limiting. After consultingthe present disclosure, one skilled in the art may envisage numerousother changes, substitutions, variations, alterations, and modificationswithout inventive activity, and it is intended that the presentdisclosure encompasses all such changes, substitutions, variations,alterations, and modifications as falling within its scope.

FIG. 1 is a block diagram illustrating an exemplary imaging system 100according to some embodiments of the present disclosure. An imagingsystem 100 may generate an image of an object. The object may include abiological object and/or a non-biological object. The biological objectmay be a human being, an animal, a plant, or a portion thereof (e.g., acell, a tissue, an organ, etc.). In some embodiments, the object may bea man-made composition of organic and/or inorganic matters that are withor without life. In the present disclosure, “object” and “subject” areused interchangeably. As illustrated, the imaging system 100 may includea scanner 110, a console 120, a processing device 130, and a display140.

The scanner 110 may scan an object, and generate a plurality of datarelating to the object. In some embodiments, the scanner 110 may be amedical imaging device, for example, a PET device, a SPECT device, a CTdevice, an MRI device, or the like, or any combination thereof (e.g., aPET-CT device, a PET-MRI device, or a SPECT-MRI device). As illustrated,the scanner 110 may include a gantry assembly 111, a detector assembly112, a cooling assembly 113, and a table 114. The gantry assembly 111may be configured to support one or more parts of the scanner 110, forexample, the detector assembly 112, the cooling assembly 113, etc. Insome embodiments, the gantry assembly 111 may include a scanning channel(or referred to as a detection channel or detection region) where theobject is positioned for scanning. More descriptions regarding thegantry assembly 111 may be found elsewhere in the present disclosure.See, e.g., FIG. 2 and the description thereof. The detector assembly 112may be configured to detect signals, for example, attenuated radioactiverays (e.g., X rays), radiation events (e.g., gamma photons), etc. Moredescriptions regarding the detector assembly 112 may be found elsewherein the present disclosure. See, e.g., FIG. 3 and the descriptionthereof. The cooling assembly 113 may be configured to produce,transfer, deliver, channel, or circulate a cooling medium to the scanner110 to absorb heat produced by the scanner 110 (e.g., the detectorassembly 112) during an imaging procedure. More descriptions regardingthe cooling assembly 113 may be found elsewhere in the presentdisclosure. See, e.g., FIG. 4 and the description thereof. The table 114may be configured to support and/or transport the object (e.g., apatient) to be scanned.

The console 120 may control the scanner 110, the processing device 130,and the display 140. The console 120 may receive signals or instructionsfrom or send information to the scanner 110, the processing device 130,the display 140, and/or other modules or units in the imaging system100. In some embodiments, the console 120 may include or provide acomputer, a program, an algorithm, software, a storage device, one ormore interfaces, etc. Exemplary interfaces may include the interfaces ofthe scanner 110, the processing device 130, the display 140, and/orother modules or units in the imaging system 100. In some embodiments,the console 120 may receive instructions from peripheral units (e.g., aninput/output) provided by a user, and send commands to the scanner 110,the processing device 130, and the display 140. In some embodiments, theconsole 120 may receive commands from the display 140 provided by, e.g.,a user, adjust the scanner 110 to detect image data of an object ofinterest, and control the processing device 130 to process the imagedata detected by the scanner 110 according to the received commands. Insome embodiments, the console 120 may control data storage of theimaging system 100. For instance, the console 120 may control thelocation of data storage, the contents of data storage, the structure ofdata storage, the indexing of the stored data, or the like, or acombination thereof.

The processing device 130 may process image data obtained from thescanner 110. For example, the processing device 130 may reconstruct animage based on the image data. In some embodiments, the processingdevice 130 may be a single server or a server group. The server groupmay be centralized or distributed. In some embodiments, the processingdevice 130 may be local or remote from other components in the imagingsystem 100. The processing device 130 may access image data stored inthe scanner 110 via a network. Alternatively, the processing device 130may be directly connected to the scanner 110 to access stored imagedata. In some embodiments, the processing device 130 may be implementedon a cloud platform. Merely by way of example, the cloud platform mayinclude a private cloud, a public cloud, a hybrid cloud, a communitycloud, a distributed cloud, an inter-cloud, a multi-cloud, or the like,or any combination thereof. In some embodiments, the processing device130 may include one or more hardware processors, such as amicrocontroller, a microprocessor, a reduced instruction set computer(RISC), an application specific integrated circuits (ASICs), anapplication-specific instruction-set processor (ASIP), a centralprocessing unit (CPU), a graphics processing unit (GPU), a physicsprocessing unit (PPU), a microcontroller unit, a digital signalprocessor (DSP), a field programmable gate array (FPGA), an advancedRISC machine (ARM), a programmable logic device (PLD), any circuit orprocessor capable of executing one or more functions, or the like, orany combinations thereof.

The display 140 may receive input and/or display output information. Theinput and/or output information may include programs, software,algorithms, data, text, number, images, voice, or the like, or anycombination thereof. For example, a user or an operator may input one ormore initial parameters or conditions to initiate a scan. As anotherexample, some information may be imported from an external resource,such as a floppy disk, a hard disk, a wireless terminal, or the like, orany combination thereof. As still another example, the display 140 maydisplay one or more images processed by the processing device 130.

It should be noted that the above description is merely provided for thepurposes of illustration, and not intended to limit the scope of thepresent disclosure. For persons having ordinary skills in the art,multiple variations and modifications may be made under the teachings ofthe present disclosure. For example, the imaging system 100 may includeone or more storage devices. However, those variations and modificationsdo not depart from the scope of the present disclosure.

FIG. 2 is a block diagram illustrating an exemplary gantry assembly 111according to some embodiments of the present disclosure. The gantryassembly 111 may include a gantry 210, a cover plate 220, and a positionadjustment device 230.

The gantry 210 may be configured to support one or more parts of thescanner 110, for example, the detector assembly 112, the coolingassembly 113, etc. As illustrated, the gantry 210 may include a maingantry 211 and a gantry base 212. In the present disclosure, “maingantry” and “main mounting plate” may be used interchangeably. The maingantry 211 may provide a main frame structure for the scanner 110. Themain gantry 211 may include a scanning channel. The gantry base 212 maybe configured to support the cooling assembly 113, the detector assembly112, the main gantry 211, and/or the cover plate 220. For example, thegantry base 212 may include a guide component corresponding to a slidingdevice of the cooling assembly 113. The main gantry 211 may be connectedwith the gantry base 212. More descriptions regarding the gantry base212 may be found elsewhere in the present disclosure. See, e.g., FIGS.19 and 20 and the description thereof.

The cover plate 220 may be configured to cover the gantry 210. In someembodiments, the cover plate 220 may include one or more cover plates,for example, a front cover plate, a back cover plate, a side cover plate(e.g., a circular cover plate), etc. The front cover plate may beconfigured to cover the front side of the gantry 210. The back coverplate may be configured to cover the back side of the gantry 210. Theside cover plate may be configured to cover the detector modules 310.

The position adjustment device 230 may be configured to adjust aposition of a component. In some embodiments, the position adjustmentdevice 230 may adjust the position of a first component relative to theposition of a second component. For example, the position adjustmentdevice 230 may adjust the position of the main gantry 211 relative tothe position of the front cover plate. More descriptions regarding theposition adjustment device 230 may be found elsewhere in the presentdisclosure. See, e.g., FIG. 9 through FIG. 11 and the descriptionthereof.

It should be noted that the above description of the diagram in FIG. 2is merely provided for the purposes of illustration, and not intended tolimit the scope of the present disclosure. For persons having ordinaryskills in the art, multiple variations or modifications may be madeunder the teachings of the present disclosure. For example, the gantryassembly 111 may further include one or more components, such as one ormore connecting pieces to connect the main gantry 211 and the gantrybase 212. As another example, the position adjustment device 230 may beunnecessary and may be omitted.

FIG. 3 is a block diagram illustrating an exemplary detector assembly112 according to some embodiments of the present disclosure. Thedetector assembly 112 may include a detector module 310, a detectorcover 320, and a detector support 330.

The detector module 310 may be configured to detect signals, forexample, attenuated radioactive rays, radiation events, etc. Merely byway of example, for a PET system, the detector module 310 may detectgamma photons. The detector module 310 of a PET system may include anelectronics unit and a detector unit. The detector unit may receiveradiation rays (e.g., gamma rays) and generate electrical signals. Theelectronics unit may collect and/or process the electrical signalsgenerated by the detector unit.

The detector cover 320 may be configured to cover the detector module310 and/or the detector support 330 circumferentially. The detectorcover 320 may protect the detector support 330 and/or the detectormodule 310 from dust and dirt. In some embodiments, the detector cover320 and the cover plate 220 may form a space for the detector module310. In some embodiments the detector cover 320 may form a space forcooling the detector module 310. The detector cover 320 may beconfigured as a side cover plate of the gantry assembly 111. In someembodiments, the detector cover 320 may be a circular shell or housing.In some embodiments, the detector cover 320 may include one or more subdetector covers. More descriptions regarding the detector cover 320 maybe found elsewhere in the present disclosure. See, e.g., FIG. 12.

The detector support 330 may be configured to support the detectormodule 310. In some embodiments, the detector support 330 may beattached to the main gantry 211. The detector support 330 may be coveredby a front cover plate, a back cover plate, and a side cover plate(e.g., the detector cover 320). The detector support 330 may beconfigured such that it surrounds the scanning channel. As illustrated,the detector support 330 may include one or more guide units 331 and aring assembly 332. The guide unit 331 may guide the positioning of thedetector module 310 for assembly or in operation. In some embodiments,the guide unit 331 may include one or more guide plates. The guideplates may be configured along an axial direction of the scanningchannel. More descriptions regarding the guide unit 331 may be foundelsewhere in the present disclosure. See, e.g., FIGS. 17 and 18 and thedescription thereof. The ring assembly 332 may include a ring made oflead or any other suitable material. For example, the ring assembly 332may be made of bismuth (Bi), platinum (Pt), lead, etc. The ring assembly332 may be configured to prevent the detector module 310 from detectingradiation rays (e.g., gamma photons) emitted from outside of a region ofinterest of an object that is located outside of an imaging area of thePET imaging device. In some embodiments, the ring assembly 332 mayinclude one or more segments. More descriptions regarding the ringassembly 332 may be found elsewhere in the present disclosure. See,e.g., FIG. 15 and the description thereof.

It should be noted that the above description of the diagram in FIG. 3is merely provided for the purposes of illustration, and not intended tolimit the scope of the present disclosure. For persons having ordinaryskills in the art, multiple variations or modifications may be madeunder the teachings of the present disclosure. For example, the detectorassembly 112 may further include one or more components, such as one ormore connecting pieces to connect the detector module 310 and thedetector support 330. As another example, the detector cover 320 and/orthe ring assembly 332 may not be necessary and may be omitted.

FIG. 4 is a block diagram illustrating an exemplary cooling assembly 113according to some embodiments of the present disclosure. The coolingassembly 113 may include a refrigerator 410, an air chamber 420, acompressor chamber 430, and an air supply chamber 440. More descriptionsregarding the cooling assembly 113 may be found elsewhere in the presentdisclosure. See, e.g., FIGS. 22 and 23.

The refrigerator 410 may process (or cool down) and drive a coolingmedium. The cooling medium may include a cooling gas (e.g., air), or acooling liquid (e.g., water). The cooling medium may absorb heat fromthe scanner 110.

As exemplified in FIG. 4, the refrigerator 410 may include a compressor411 and an air blower 412 when the cooling medium is a gas (e.g., air).In some embodiments, the compressor 411 may use a cryogen and/or arefrigerant to cool the cooling medium. The compressor 411 (alsoreferred to as a heat exchanger) may increase the pressure of thecryogen, and then, the cryogen may be condensed, and the heat in thecryogen may dissipate to a heat sink (not shown). In some embodiments,condensed cryogen may evaporate in an evaporator (not shown), and absorbheat from the cooling medium, and then the cooling medium may be cooleddown. In some embodiments, the compressor 411 may include a shell andtube heat exchanger, a pillow plate heat exchanger, a fluid heatexchanger, a dynamic scraped surface heat exchanger, a phase-change heatexchanger, a direct contact heat exchanger, or the like, or anycombination thereof. The air blower 412 (e.g., a fan) may drive thecooling medium into one or more cooling medium passages. The coolingmedium passages may channel the cooling medium to one or more targetlocations (e.g., around the detector module 310) of the scanner 110. Insome embodiments, the air blower 412 may regulate the flow rate of thecooling medium. The flow rate of the cooling medium may be regulatedthrough the variation of the rotation speed of the air blower 412.

The air chamber 420 may be configured as part of the cooling mediumpassages. As illustrated, the air chamber 420 may include an inletchamber 421 and a return chamber 422. The inlet chamber 421 may connectthe air blower 412 and a chilling chamber. The chilling chamber may beconfigured with one or more heating components (e.g., the detectormodule 310) of the scanner 110. The return chamber 422 may connect thechilling chamber and the compressor 411. The compressor chamber 430 maybe configured with the compressor 411. The air supply chamber 440 may beconfigured to feed air to the air blower 412.

FIG. 4 illustrates an exemplary configuration of a cooling assembly thatuses air (or another type of gas or a mixture of different types ofgases as the cooling medium. A cooling assembly that uses a liquidcooling medium may be configured similarly. It should be noted that theabove description of the diagram in FIG. 4 is merely provided for thepurposes of illustration, and not intended to limit the scope of thepresent disclosure. For persons having ordinary skills in the art,multiple variations or modifications may be made under the teachings ofthe present disclosure. For example, the cooling assembly 113 mayfurther include one or more components, such as one or more thermalinsulation layers. The thermal insulation layers may prevent or reduceheat exchange between the cooling medium in different chambers thatshare a common surface.

FIGS. 5A and 5B illustrate structural components of an exemplary scanner110 according to some embodiments of the present disclosure. Asillustrated in FIG. 5A, the scanner 110 may include a main gantry 501(also referred to as a shared plate 520), a scanning channel 502, achilling chamber 503, a detector cover 504, a limit plate 515, an airintake 506, an air outlet 507, a guide unit 508, and a limit piece 509.The main gantry 501 may be the same as or similar to the main gantry211. The scanning channel 502 may define an imaging area where theobject may be positioned to be scanned or imaged. The chilling chamber503 may be configured to cool the heat generating components of thescanner 110. In some embodiments, the chilling chamber 503 may bedivided into a plurality of sub chambers. The detector cover 504 may bethe same as or similar to the detector cover 320. The limit plate 515may divide the chilling chamber 503 into two or more sub chambers. Thechilling chamber 503 may include the air intake 506 and the air outlet507. In some embodiments, the air intake 506 and the air outlet 507 maybe configured on each sub chamber of the chilling chamber 503. In someembodiments, a sub chamber may contain a detector unit.

The guide unit 508 may be configured on a detector support around thescanning channel 502 to guide the positioning of the detectors forassembly or in operation. In some embodiments, the guide unit 508 may bea guide plate as illustrated in FIGS. 18A and 18B. In some embodiments,the guide unit 508 may be a guide column as illustrated in FIG. 18C. Thelimit piece 509 may be configured on the guide unit 508 to limit thedetector modules from sliding off the guide unit 508. In someembodiments, the limit piece 509 may be located at one end of the guideunit 508 away from the main gantry 501. The limit piece 509 may restrictthe position of the detector modules relative to the guide unit 508. Insome embodiments, in the assembly of a scanner, the detector modules mayslide along the guide unit 508 and then be fixed in position by thelimit piece 509. In some embodiments, the detector modules may be fixedin position using the limit piece 509, without using one or more screwson the detector modules themselves. Thus, the assembly and disassemblyof the detector modules may be simplified. The limit piece 509 may be athin stripe mounted using, e.g., one or more screws, on one end of thelimit plate 515 that is away from the main gantry 501. In someembodiments, the guide unit 508 may be arranged perpendicular to a frontside of the main gantry 501. Thus, a technician may stand at one sideopposite to the front side of the main gantry 501 and handle (e.g.,assemble, maintain, dissemble) the detector modules. In someembodiments, the guide unit 508 may include a guide plate arranged alongan axial direction of the scanning channel 502, the guide plate mayinclude a guide rail, and the detector module(s) may include at leastone guide piece complementary to the guide rail.

In some embodiments, the limit piece 509 may include one or more sublimit pieces. One or more sub limit pieces may be used with a detectormodule. In some embodiments, a detector module may be limited by one sublimit piece. In some embodiments, each detector module may have acorresponding limit piece (or sub limit piece). Thus, a technician maydissemble and/or maintain the detector module by removing the sub limitpiece, without dissembling the whole limit piece 509. The maintenance ofthe detector modules may be simplified in this way. In some embodiments,the limit piece 509 may be configured as an integral part to limit aplurality of detector modules. As shown in an enlarged view of the limitpiece 509 in FIG. 5A, the limit piece 509 may have a curved shape (e.g.,the shape of a ring, an arc, etc.). When assembling the detectormodules, a technician may slide the detector modules along the guideunit 508, and then the detector modules may be limited by the limitpiece 509. It should be noted that the limit piece 509 described in thepresent disclosure is merely an exemplary mechanism for fixing thepositions of a plurality of detector modules. The positions of theplurality of detector modules may be fixed in other ways, for example,by way of engagement.

As illustrated in FIG. 5B, the scanner 110 may include a gantry 510, afirst ring 511 (including one or more first segments 512), a second ring513 (including one or more second segments 522), one or more handles514, one or more limit plates 515 (also referred to as guide plates insome embodiments), a detector cover 516, a scanning channel space 517(also referred to as a scanning channel 518), and one or more detectormodules 519 (also referred to as the detector assembly 112). The gantry510 may be the same as or similar to the main gantry 501. In someembodiments, the first ring 511 or the second ring 513 may beunnecessary. The limit plates 515 may be fixed on the gantry 510 alongthe axial direction of the scanning channel 518 (i.e., the Z axis) viaone or more screws. In some embodiments, the orientation of the limitplates 515 may be perpendicular to a front side of the gantry 510. Adetector module 519 may be the same as or similar to the detector module310 including one or more electronics units and one or more detectorunits. In the present disclosure, the X axis direction shown in FIG. 5Bmay be from the right side to the left side of the gantry 510. The Yaxis direction shown in FIG. 5B may be from the upper part to the lowerpart of the gantry 510. The Z axis direction shown in FIG. 5B may befrom the front side to the rear side of the gantry 510 along the axis ofthe scanning channel 518. In some embodiments, the detector assembly 112may have a first side and a second side along an axial direction of thescanning channel 502. The first side may be closer to the front face ofthe scanning channel 502. In some embodiments, the detector assembly 112may include a first ring 511 located on the first side of the detectorassembly 112 and a second ring 513 located on the second side of thedetector assembly 112. In some embodiments, at least one of the firstring 511 or the second ring 513 may include at least two segments. Insome embodiments, the first ring 511 and/or the second ring 513 mayinclude a flange including a protrusion toward the detector modules 519.

The first segments 512 may be fixed on an edge of the scanning channel518, forming the first ring 511. The first ring 511 may be closer to thefront side of the gantry 510 than the limit plates 515. Before thedetector modules 519 are assembled, the first ring 511 and the limitplates 515 may be fixed on the gantry 510. Then one of the detectormodules 519 may be fixed between two adjacent limit plates 515 bysliding on one or more guiding rails (not shown in FIG. 5B). The guidingrail(s) may be mounted or formed (e.g., carved) on the limit plates 515and arranged along the axial direction of the scanning channel 518(i.e., the Z axis). The immobilization of a detector module 519 and thelimit plates 515 in the radial direction of the scanning channel 518 maybe realized through the guiding rail(s). Further, the second segments522 may be fixed on an end of the limit plates 515 that is away from thegantry 510, forming the second ring 513. The first ring 511 and thesecond ring 513 may be configured to block undesired gamma photons fromentering the scanning channel 518. The second ring 513 may restrict theposition of the detector modules 519 relative to the limit plates 515along the axial direction of the scanning channel 518. The number of thesecond segments 522 may relate to the number of the limit plates 515.The number of the limit plates 515 may relate to the number of thedetector modules 519. Accordingly, the number of the second segments 522may relate to the number of the detector modules 519. In someembodiments, the number of the detector modules 519 is an integralmultiple of the number of the second segments 522. The integral multiplemay be 2, 3, 4, 5, etc. Merely by way of example, if the number of thedetector modules 519 is 26, the number of the second segments 522 may behalf of that of the detector modules 519, i.e., 13. In some embodiments,a technician may dissemble and/or maintain a specific detector module519 by removing a corresponding second segment 522 that limits thespecific detector module 519, without dissembling the whole second ring513. The maintenance of the detector modules may be simplified in thisway. In some embodiments, a handle 514 may be mounted on a side of asecond segment 522 away from a detector module 519. The handles 514 maybe of a U shape, a T shape, an L shape, etc. The handles 514 mayfacilitate the handling (e.g., assembly, maintenance, disassembly) ofthe second segments 522. More descriptions regarding the first ring 511and/or the second ring 513 may be found elsewhere in the presentdisclosure. See, e.g., FIGS. 15 and 16 and the description thereof.

FIG. 6A illustrates a front view of an exemplary scanner 110 accordingto some embodiments of the present disclosure. As illustrated in FIG.6A, the scanner 110 may include a main gantry 601 (also referred to as amain mounting plate), one or more guide plates 602, one or more detectormodules 604, and a scanning channel 605. In some embodiments, the maingantry 601 and the main gantry 501 (or the gantry 510) may be the sameor different. The guide plates 602 may correspond to the limit plates515 as discussed in connection with FIG. 5. In some embodiments, thelimit plate(s) 515 may take a form different from the guide plate(s)602. For instance, the limit plate(s) 515 may take the form of one ormore guide pieces 603. The region B shown in FIG. 6A may illustrate onedetector module 604 and two corresponding guide plates 602. Moredescriptions regarding the region B may be found elsewhere in thepresent disclosure. See, e.g., FIG. 17A and the description thereof.

FIG. 6B illustrates a front view of an exemplary scanner 110 accordingto some embodiments of the present disclosure. As illustrated in FIG.6B, the scanner 110 may include a detector cover 606, a front coverplate 607, a gantry base 608, and a scanning channel 609. The frontcover plate 607 may be substantially vertical. In some embodiments, thefront cover plate 607 and the main gantry 601 may be the same ordifferent. In some embodiments, the scanning channel 609 and thescanning channel 605 may be the same or different. The gantry base 608may be located on the bottom of the scanner 110.

FIG. 6C is a schematic diagram illustrating an exemplary scanner 110according to some embodiments of the present disclosure. As illustratedin FIG. 6C, the scanner 110 may include a gantry 610, a scanning channel611, one or more detector modules 612, and a cooler 613. In someembodiments, the gantry 610 and the main gantry 601 may be the same ordifferent. In some embodiments, the scanning channel 611 and thescanning channel 605 may be the same or different. The cooler 613 may bethe same as or similar to the cooling assembly 113.

FIG. 6D is a schematic diagram illustrating an exemplary scanner 110according to some embodiments of the present disclosure. As illustratedin FIG. 6D, the scanner 110 may include a shared plate 614 (alsoreferred to as a gantry 615), a scanning channel 616, one or morechilling chambers 617, a detector cover 618, one or more air intakes 619for an inlet chamber, an inlet chamber port 620, one or more air outlets621 for a return chamber, and a return chamber port 622. The air intakes619 may be configured on the chilling chamber 617. The air outlets 621may be configured on the chilling chamber 617. The air intakes 619 maybe connected to the air outlets 621 to form a passage for air. In someembodiments, an inlet chamber, a return chamber, the inlet chamber port620, and/or the return chamber port 622 may be configured on the sharedplate 614. In some embodiments, the shared plate 614 and the main gantry601 may be the same or different. In some embodiments, the shared plate614 and the shared plate 520 may be the same or different. In someembodiments, the scanning channel 616 and the scanning channel 605 maybe the same or different. In some embodiments, the detector cover 618and the detector cover 504 may be the same or different. In someembodiments, the chilling chamber 617 and the chilling chamber 503 maybe the same or different. In some embodiments, the air intakes 619 andthe air intake 506 may be the same or different. In some embodiments,the air outlets 621 and the air outlets 507 may be the same ordifferent.

FIGS. 7A and 7B illustrate side views of exemplary scanners 110according to some embodiments of the present disclosure. As illustratedin FIG. 7A, a scanner 110 may include a detector cover 701, a frontcover plate 702, and a gantry base 703. In some embodiments, the frontcover plate 702 and the front cover plate 607 may be the same ordifferent. In some embodiments, the detector cover 701 and the detectorcover 606 may be the same or different. In some embodiments the gantrybase 703 and the gantry base 608 may be the same or different. Asillustrated in FIG. 7B, a scanner 110 may include a gantry 704, a firstring 705, a first flange 706, a second ring 707, a handle 708, a secondflange 709, one or more limit plates 710, and one or more detectormodules 711. The first flange 706 may be formed on the first ring 705.The second flange 709 may be formed on the second ring 707. The firstflange 706 and the second flange 709 may bulge toward the detectormodules 711. The first flange 706 and the second flange 709 may blockundesirable radiation rays (e.g., gamma photons) emitted by an objectpositioned outside an imaging region. In some embodiments, a front faceof the detector cover 701 may include at least one first flange (e.g.,the first flange 706). The first flange may include a protrusion towardan axial direction of the detector cover 701. In some embodiments, aback face of the detector cover 702 may include at least one secondflange (e.g., the second flange 709). The second flange may include aprotrusion toward an axial direction of the detector cover 701. In someembodiments, the detector cover 701 may be connected to the front coverplate 702 by the first flange 706 and be connected to a back cover plate(not shown) by the second flange 709. In some embodiments, the frontcover plate 702, the detector cover 701, the back cover plate, and asidewall of a scanning channel (not shown) may surround a detectorsupport of the detector modules 711. In some embodiments, the gantry 704and the gantry 510 may be the same or different. In some embodiments,the gantry 704 and the front cover plate 702 may be the same ordifferent. In some embodiments, the detector modules 711 and thedetector modules 519 may be the same or different. In some embodiments,the first ring 705 and the first ring 511 may be the same or different.In some embodiments, the second ring 707 and the second ring 513 may bethe same or different. In some embodiments, the limit plates 710 and thelimit plates 515 may be the same or different. In some embodiments, thehandle 708 and the handle 514 may be the same or different.

FIGS. 8A through 8C illustrate three views of an exemplary scanner 110including a position adjustment device according to some embodiments ofthe present disclosure. As illustrated in FIGS. 8A to 8C, the scanner110 may include a front cover plate 801, a gantry 802, and a positionadjustment device 803. In some embodiments, the front cover plate 801and the front cover plate 702 may be the same or different. The positionadjustment device 803 may be configured to connect a first component(e.g., the front cover plate 801) and a second component (e.g., thegantry 802), and adjust a relative position between the first componentand the second component. In some embodiments, the first component andthe second component may be connected via at least one (or two, three,etc.) position adjustment device 803. Merely by way of example, thefirst component and the second component may be connected via twoposition adjustment devices 803. As illustrated in FIG. 8B, the twoposition adjustment devices 803 may be located on two different sides ofthe second component (e.g., the gantry 802) and attached to the firstcomponent (e.g., the front cover plate 801). The position adjustmentdevice 803 may include one or more bulged ends, one or more slidingholes configured on the bulged ends, a fixed pin, a fixed hole, etc., asexemplified in FIGS. 9A-9D. The fixed pin may include a fixed plane, apin, etc., as exemplified in FIG. 10. The position adjustment device 803may be connected to the gantry 802 via the bulged ends and the slidingholes. The fixed pin may be used to attach, by inserting into the fixedhole, the position adjustment device 803 to a side of the front coverplate 801 that is close to the gantry 802.

FIG. 9A illustrates an exemplary position adjustment device 803according to some embodiments of the present disclosure. As illustrated,the position adjustment device 803 may include a fixed hole 908, asecond fastener 912, a housing 913, and one or more sliding holes 914.In some embodiments, the position adjustment device 803 may furtherinclude one or more protruding ends 915. The fixed hole 908 mayaccommodate a pin (e.g., a pin 1002 of a fixed pin 1000 shown in FIG.10). The pin 1002 may pass through the fixed hole 908 and fix via ascrew. The second fastener 912 may be configured to fix an adjustmentpiece (e.g., a second adjustment piece 911 shown in FIG. 9C). The secondfastener 912 may be configured on the housing 913 via a screw (e.g., ascrew 903 shown in FIG. 9D). The sliding holes 914 may be configured tofacilitate the attachment of the position adjustment device 803 onto acomponent (e.g., the front cover plate 801). The sliding holes 914 maybe located on the protruding end 915.

FIG. 9B illustrates a side view of an exemplary position adjustmentdevice 803 according to some embodiments of the present disclosure. Theside view may be in a Y-Z plane shown in FIG. 9A. As illustrated in FIG.9B, the position adjustment device 803 may include a first adjustmentpiece 906, one or more sliding holes 914, and one or more protrudingends 915. A protruding end 915 may be located on one side of the housing913 (see FIGS. 9A, 9C, and 9D). The housing 913 may be movable along theZ axis direction. As illustrated in FIGS. 9A and 9D, the protruding end915 may be longer than the housing 913 along the Y axis direction. Theprotruding end 915 may be configured with a sliding hole 914. Thesliding hole 914 may be configured to facilitate the attachment of theposition adjustment device 803 onto a component whose position may beadjusted by the position adjustment device 803. One or more screws maypass through the sliding holes 914 and then attach the positionadjustment device 803 onto the component. In some embodiments, thesliding hole 914 may be of a stripe shape, a rectangular shape, a circleshape, etc. Merely by way of example, for the sliding hole 914 having astripe shape (e.g., the long axis of the stripe is along the Z axisdirection), the housing 913 may be moved along the Z axis by moving thescrews along the long axis of the sliding hole 914. In some embodiments,the screws may need to be loosened before moving the housing 913.

FIG. 9C illustrates a bottom view of an exemplary position adjustmentdevice 803 according to some embodiments of the present disclosure. Thebottom view may be in an X-Z plane shown in FIG. 9A. As illustrated inFIG. 9C, the position adjustment device 803 may include one or morefirst adjustment holes 902 (not shown in FIG. 9C), a second adjustmentpiece 911, the second fastener 912, the housing 913, and a protrudingend 915. In some embodiments, one or more screws 903 may be located inthe first adjustment holes 902. The first adjustment holes 902 may beformed on a fastener (e.g., the second fastener 912).

FIG. 9D illustrates a sectional view taken along E-E′ of FIG. 9Caccording to some embodiments of the present disclosure. The sectionalview may be in the X-Y plane shown in FIG. 9A. As illustrated in FIG.9D, the position adjustment device 803 may include one or more secondadjustment holes 901, the first adjustment holes 902, one or more screws903, a first moving piece 904, a first sliding cavity 905, the firstadjustment piece 906, a first fastener 907, the fixed hole 908, a secondmoving piece 909, a second sliding cavity 910, the second adjustmentpiece 911, the second fastener 912, the housing 913, the sliding holes914, and the protruding end(s) 915. The position adjustment device 803may be configured to connect a first component (not shown in the FIG.9D) and a second component (not shown in the FIG. 9D). Merely by way ofexample, the position adjustment device 803 may be mounted on the firstcomponent, and the first moving piece 904 of the position adjustmentdevice 803 may be fixed onto or otherwise mechanically connected to thesecond component.

The first adjustment piece 906 may be mechanically connected to thefirst moving piece 904 and adjust the position of the first moving piece904. The second adjustment piece 911 may be mechanically connected tothe second moving piece 909 and adjust the position of the second movingpiece 909. The second moving piece 909 may be mechanically connect tothe first moving piece 904. The first adjustment piece 906 may adjustthe position of the first moving piece 904 by causing the first movingpiece 904 to move along a first direction. The first component may bedriven by the first moving piece 904 and move accordingly (e.g., alongthe first direction). The second adjustment piece 911 may adjust theposition of the second moving piece 909 by causing it to move along asecond direction. The first moving piece 904 may be driven by the secondmoving piece 909 and move accordingly (e.g., along the seconddirection). The first moving piece 904 may be caused to move along thefirst direction only, the second direction only, a third direction only,or two or three of the first direction, the second direction, and thethird direction. In some embodiments, the first direction may be the Xaxis direction, and the second direction may be the Y axis direction.

The first sliding cavity 905 may be configured to allow the first movingpiece 904 to move along the first direction (e.g., the X axisdirection). The first sliding cavity 905 may be located within thesecond moving piece 909. In some embodiments, the first sliding cavity905 may have the shape of a cuboid. Accordingly, the first moving piece904 may be a cuboid. The first moving piece 904 may move in the firstsliding cavity 905 along one direction. The second sliding cavity 910may be configured to allow the second moving piece 909 to move along thesecond direction (e.g., the Y axis direction). The second sliding cavity910 may be configured in the housing 913.

In some embodiments, the first adjustment piece 906 may be a screwengaged in the second moving piece 909. In some embodiments, the screwmay include a hexagon socket head cap screw. The first adjustment piece906 and the first moving piece 904 may be connected by way of, e.g., athreaded engagement. The first moving piece 904 may be caused to move inthe first sliding cavity 905 along the first direction by adjusting thescrew.

The first fastener 907 may hold the first adjustment piece 906 in placein the second moving piece 909 and prevent the first adjustment piece906 from falling out of the second moving piece 909. In someembodiments, the first fastener 907 may be a sheet. The sheet may bemade of a metal material, for example, iron, copper, etc., or an alloythereof. The sheet may be fixed on the second moving piece 909 via thescrew 903. In some embodiments, the first fastener 907 may have one ormore first adjustment holes 902. A screwdriver may pass through thefirst adjustment holes 902, and reach and adjust the first adjustmentpiece 906 (e.g., a hexagon socket head cap screw). The diameter of thefirst adjustment holes 902 may be less than the first adjustment piece906 (e.g., the hexagon socket head cap screw). For instance, thediameter of the first adjustment hole 902 may be less than the diameterof the hexagon socket head of the first adjustment piece 906.Accordingly, the first adjustment piece 906 may be hold in place in thesecond moving piece 909.

Similarly, the second adjustment piece 911 may be a screw. In someembodiments, the screw may include a hexagon socket head cap screw. Insome embodiments, the second fastener 912 may hold the second adjustmentpiece 911 in place in the housing 913 and prevent the second adjustmentpiece 911 from falling out of the housing 913. The second fastener 912may be fixed on the housing 913 via the screw 903. In some embodiments,the second fastener 912 may have one or more first adjustment holes 902.The diameter of the first adjustment holes 902 may be less than thesecond adjustment piece 911 (e.g., the hexagon socket head cap screw).For instance, the diameter of the first adjustment hole 902 may be lessthan the diameter of the hexagon socket head of the second adjustmentpiece 911. Accordingly, the second adjustment piece 911 may be hold inplace in the housing 913.

The housing 913 may have one or more second adjustment holes 901. Asecond adjustment hole 901 may be configured to provide passage spacefor a tool (e.g., a screwdriver) to access and adjust, from the outsideof the housing 913, the first adjustment piece 906 by causing the firstadjustment piece 906 to move along the X axis direction. In someembodiments, the dimension of a second adjustment hole 901 in the seconddirection may be greater than the largest distance that the secondmoving piece 909 is allowed to move along the second direction (e.g.,the Y axis direction). Accordingly, the first adjustment piece 906engaged or nested in the second moving piece 909 is movable along the Yaxis direction by causing the second moving piece 909 to move. In someembodiments, the housing 913 may be regarded as a third moving piece andmay move along a third direction. The third direction may be the Z axisdirection shown in FIG. 9A.

For illustration purposes, an adjustment process of the positionadjustment device 803 is provided. The position adjustment device 803may be configured to connect a front cover plated (e.g., the front coverplate 801 in FIG. 8A) and a gantry (e.g., the gantry 802 in FIG. 8A).For example, the position of the front cover plate may be adjusted alongthe X axis direction by adjusting the first adjustment piece 906. Thefirst adjustment piece 906 may drive the first moving piece 904 to move.Accordingly, the movement of the first moving piece 904 may drive thefront cover plate to move along the X axis direction. As anotherexample, the position of the front cover plate may be adjusted along theY axis direction by adjusting the second adjustment piece 911. Thesecond adjustment piece 911 may drive the second moving piece 909 tomove. The movement of the second moving piece 909 may drive the firstmoving piece 904 to move. Accordingly, the movement of the first movingpiece 904 may drive the front cover plate to move along the Y axisdirection. As still another example, the position of the front coverplate may be adjusted along the Z axis direction (as illustrated in FIG.9A) by moving the third moving piece (i.e., the housing 913) along thevertical axis of the sliding hole 914 (i.e., the Z axis). The movementof the housing 913 may drive the second moving piece 909 to move. Themovement of the second moving piece 909 may drive the first moving piece904 to move. Accordingly, the movement of the first moving piece 904 maydrive the front cover plate to move along the Z axis. In someembodiments, before the housing 913 is moved, the screw(s) inserted intothe sliding holes 914 may need to be loosened. In some embodiments, theposition of the front cover plate may be adjusted in more than onedirection by the coordination of at least two components of the firstadjustment piece 906, the second adjustment piece 911, the first movingpiece 904, the second moving piece 909, or the housing 913.

FIG. 10 illustrates an exemplary fixed pin 1000 according to someembodiments of the present disclosure. The fixed pin 1000 may beconfigured to mechanically connect two components. For instance, thefixed pin 1000 may mechanically connect the first moving piece 904 ofthe position adjustment device 803 with another component (e.g., thegantry 802). As illustrated, the fixed pin 1000 may include a fixedplane 1001 and a pin 1002. The pin 1002 may include a fixed ring 1003and a screw hole 1004. With reference to the example in which the fixedpin 1000 is used to mechanically connect the first moving piece 904 ofthe position adjustment device 803 with the gantry 802, the fixed plane1001 may contact a surface of the gantry 802. The pin 1002 may beinserted into the fixed hole 908 of the position adjustment device 803.The fixed ring 1003 may be configured as a limit piece to limit theinsertion depth of the pin 1002 into the fixed hole 908. Additionally, ascrew corresponding to the screw hole 1004 may be used to fix the fixedpin 1000 on the position adjustment device 803. In some embodiments, thefirst moving piece 904 and the fixed pin 1000 may be configured as anintegral piece. It should be noted that the description above is merelyan example of a connection between the first moving piece 904 of theposition adjustment device 803 with another component, and is notintended to be limiting.

FIG. 11A illustrates an exemplary position adjustment device 803according to some embodiments of the present disclosure. The positionadjustment device 803 may include one or more sliding cavities and oneor more moving pieces. In some embodiments, the position adjustmentdevice 803 may adjust the relative position between the first componentand the second component in various directions. A moving piece may benested within another moving piece. A moving piece and another movingpiece nested therein may be mechanically connected via an adjustmentpiece such that the two moving pieces may move relative to each otheralong a certain direction. As illustrated in FIG. 11A, the positionadjustment device 803 may include a first moving piece 1101, a firstsliding cavity 1102, a second moving piece 1104, a second sliding cavity1105, a third moving piece 1107, a third sliding cavity 1108, a fourthmoving piece 1110, a fourth sliding cavity 1111, and a fifth movingpiece 1112. The first moving piece 1101 may move along a direction AA′in the first sliding cavity 1102 located inside the second moving piece1104. The second moving piece 1104 may move along a direction BB′ in thesecond sliding cavity 1105 located inside the third moving piece 1107.The third moving piece 1107 may move along a direction CC′ in the thirdsliding cavity 1108 located inside the fourth moving piece 1110. Thefourth moving piece 1110 may move along a direction DD′ in the fourthsliding cavity 1111 located inside the fifth moving piece 1112.

FIG. 11B illustrates an exemplary position adjustment device 803according to some embodiments of the present disclosure. The positionadjustment device 803 may include one or more sliding rails and one ormore moving pieces. A moving piece may be nested within another movingpiece. A moving piece and another moving piece nested therein may bemechanically connected via an adjustment piece such that the two movingpieces may move relative to each other along a certain direction. Insome embodiments, an adjustment piece may be a sliding rail. Asillustrated in FIG. 11B, the position adjustment device 803 may includea first moving piece 1113, a first sliding rail 1103, a second movingpiece 1114, a second sliding rail 1106, a third moving piece 1115, athird sliding rail 1109, and a fourth moving piece 1116. The firstmoving piece 1113 may move along the first sliding rail 1103 configuredon a side of the second moving piece 1114. The second moving piece 1114may move along the second sliding rail 1106 configured on a side of thethird moving piece 1115. The third moving piece 1115 may move along athird sliding rail 1109 configured on a side of the fourth moving piece1116. In some embodiments, a sliding rail may be configured on an upperside, a bottom side, a left side, a right side, a front side, a rearside, an interior side, an exterior side, etc., of a moving piece.

It should be noted that the description in FIGS. 11A and 11B is merelyan example of the position adjustment device 803, and is not intended tobe limiting. For example, the position adjustment device 803 may beconfigured with a plurality of sliding cavities or sliding rails. Forpurposes of illustration, the position adjustment device 803 may includeN moving pieces and N adjustment pieces corresponding to the N movingpieces. The N moving pieces may move along N directions. The nth movingpiece (n is equal to or lower than N) may be connected to the (n−1)thmoving piece. The nth moving piece may move along an nth direction withthe assistance of an nth adjustment piece. At the same time, the (n−1)thmoving piece may be driven to move along the nth direction. The number Nmay be a positive integer not less than 2. As another example, theposition adjustment device 803 may be configured with a plurality ofsliding cavities and a plurality of sliding rails. Merely by way ofexample, the position adjustment device 803 may include M slidingcavities and (N-M) sliding rails. The number M may be a positive integerless than or equal to N.

FIG. 12A illustrates an exemplary detector cover 320 according to someembodiments of the present disclosure. In some embodiments, the detectorcover 320 may include one or more sub detector covers. FIG. 12Cillustrates a top view of the detector cover 320 shown in FIG. 12Aaccording to some embodiments of the present disclosure. As illustratedin FIGS. 12A and 12C, the detector cover 320 may include a first subdetector cover 1201, a second sub detector cover 1202, a third subdetector cover 1203, a fourth sub detector cover 1204, a fifth subdetector cover 1205, a sixth sub detector cover 1206, one or more dataand power interfaces 1207, and a flanging structure 1208. In someembodiments, at least two of the sub detector covers of the detectorcover 320 may have a same or similar structure. In some embodiments, atleast two of the sub detector covers of the detector cover 320 may havedifferent structures. For instance, the first sub detector cover 1201,the third sub detector cover 1203, the fourth sub detector cover 1204,and the sixth sub detector cover 1206 may have a similar structure,designated as a first-type sub detector cover 1210; the second subdetector cover 1202 and the fifth sub detector cover 1205 may have asimilar structure, designated as a second-type sub detector cover 1220.The first-type sub detector cover 1210 may be the same as, similar to,or different from the second-type sub detector cover 1220.

The flanging structure 1208 may be located at a side wall of thedetector cover 320 along the Z axis of the detector cover 320. In theside wall of the detector cover 320, the long axis of the flangingstructure 1208 may be in a direction from a front end (see the arrowlabeled as “FE” in FIG. 12C) to a back end (see the arrow labeled as“BE” in FIG. 12C) of the detector cover 320. The Z axis here may be thesame as that illustrated in FIG. 9A. The flanging structure 1208 at thefront end may facilitate the mounting of the detector cover 320 onto themain gantry 211 of a medical imaging device (e.g., a PET device), andthe flanging structure 1208 at the back end may facilitate the mountingof the detector cover 320 on the back cover plate of the medical imagingdevice. In some embodiments, the main gantry, the detector cover 320,the back cover plate, and/or a sidewall of the scanning channel mayencompass the detector support 330. In some embodiments, the detectorcover 320 may form an isolated space surrounding the detector module310. The isolated space may be separate from the space between thedetector cover 320 and the cover plate 220 of the gantry assembly 111.In some embodiments, the isolated space may assist to improve thecooling efficiency of the cooling assembly 113.

FIG. 12B illustrates an exemplary detector cover 320 according to someembodiments of the present disclosure. The detector cover 320 mayinclude one or more first-type sub detector covers 1210 and one or moresecond-type sub detector covers 1220. In some embodiments, thefirst-type sub detector cover 1210 and the second-type sub detectorcover 1220 may have the same or similar structure. In some embodiments,the first-type sub detector cover 1210 and the second-type sub detectorcover 1220 may have different structures. In some embodiments, thesecond-type sub detector cover 1220 may fill the space between thefirst-type sub detector cover 1210 such that the detector cover 320maintains a desirable shape (e.g., the shape of a circle, an ellipse, apolygon, etc.). In some embodiments, the second-type sub detector cover1220 may be held in place by one or more first-type sub detector covers1210. In some embodiments, the first-type sub detector cover 1210 may befixed on the gantry. Merely by way of example, the first-type subdetector cover 1210 may be fixed on the gantry via one or more screws.The second-type sub detector cover 1220 may be connected to thefirst-type sub detector cover 1210. The connection between thesecond-type sub detector cover 1220 and the first-type sub detectorcover 1210 may be formed by way of overlapping, mortise, occlusion,engagement, or the like, or any combination thereof.

In some embodiments, one sub detector cover in every few sub detectorcovers (e.g., every other sub detector cover, one in every three subdetector cover, etc.) may be fixed on the gantry, regardless of its typebeing the first-type sub detector cover 1210 or the second-type subdetector cover 1220. For illustration purposes, a detector coverincluding the first-type sub detector cover(s) 1210 and the second-typesub detector cover(s) 1220 is used below as an example. In someembodiments, the detector cover 320 may include n first-type subdetector covers 1210 (e.g., a first first-type sub detector cover1210-1, a second first-type sub detector cover 1210-2, a thirdfirst-type sub detector cover 1210-3, a fourth first-type sub detectorcover 1210-4, . . . , an nth first-type sub detector cover 1210-n) and nsecond-type sub detector covers 1220 (e.g., a first second-type subdetector cover 1220-1, a second second-type sub detector cover 1220-2, athird second-type sub detector cover 1220-3, a fourth second-type subdetector cover 1210-4, . . . , an nth second-type sub detector cover1220-n). In some embodiments, a first-type sub detector cover 1210 mayhave a stripe shape with two ends, each end of which includes a bulgeand a groove. A second-type sub detector cover 1220 may have a stripeshape with two ends, each of which includes a bulge and a groove. Insome embodiments, the first first-type sub detector cover 1210-1 may befixed on the gantry. The bulge of the first second-type sub detectorcover 1220-1 may be inserted into the groove of the first first-type subdetector cover 1210-1. The bulge of the second first-type sub detectorcover 1210-2 may then be inserted into the groove of the firstsecond-type sub detector cover 1220-1. The bulge of an nth second-typesub detector cover 1220-n may be inserted into the groove of an nthfirst-type sub detector cover 1210-n. Similarly, the bulge of the firstfirst-type sub detector cover 1210-1 may be inserted into the groove ofthe nth second-type sub detector cover 1220-n. In this way, the assemblyand disassembly of the detector cover 320 may be facilitated.

FIG. 12D illustrates a sectional view from L-L′ of FIG. 12C according tosome embodiments of the present disclosure. As illustrated, the detectorcover 320 may include four first-type sub detector covers (the first subdetector cover 1201, the third sub detector cover 1203, the fourth subdetector cover 1204, and the sixth sub detector cover 1206), twosecond-type sub detector covers (the second sub detector cover 1202 andthe fifth sub detector cover 1205), and two data and power interfaces1207. In some embodiments, the structures and/or sizes of the six subdetector covers may be the same or different. If the structures andsizes of the four first-type sub detector covers are the same, the fourfirst-type sub detector covers may be used interchangeably. Similarly,if the structures and sizes of the two second-type sub detector coversare the same, the two second-type of sub detector covers may be usedinterchangeably. In some embodiments, the detector cover 320 may includesix sub detector covers, and the second-type sub detector covers mayinclude a top sub detector cover (e.g., the second sub detector cover1202) and/or a bottom sub detector cover (e.g., the fifth sub detectorcover 1205). In some embodiments, a plurality of first-type sub detectorcovers and a plurality of second-type sub detector covers may bearranged alternately.

In some embodiments, the first sub detector cover 1201 and the third subdetector cover 1203 may be fixed firstly to assemble the detector cover320. The second sub detector cover 1202 may then be placed in acorresponding position between the first sub detector cover 1201 and thethird sub detector cover 1203. The assembly process may be repeated withrespect to the fourth sub detector cover 1204, the fifth sub detectorcover 1205, and the sixth sub detector cover 1206. A first data andpower interface 1207 may be assembled between the first sub detectorcover 1201 and the sixth sub detector cover 1206. A second data andpower interface 1207 may be assembled between the third sub detectorcover 1203 and the fourth sub detector cover 1204. The region A shown inFIG. 12D may include a connection between a first-type sub detectorcover (e.g., the first sub detector cover 1201) and a second-type subdetector cover (e.g., the second sub detector cover 1202). The region Bshown in FIG. 12D may include a connection between a data and powerinterface 1207 and two first-type sub detector covers (e.g., the firstsub detector cover 1201 and the sixth sub detector cover 1206). Moredescriptions regarding the region A and the region B may be foundelsewhere in the present disclosure. See, e.g., FIGS. 13A and 13B andthe description thereof. It should be noted that the detector cover 320shown in FIGS. 12A through 12D may be the same as or different from thedetector cover 504 shown in FIG. 5A, the detector cover 606 shown inFIG. 6B, the detector cover 618 shown in FIG. 6D, and/or the detectorcover 701 shown in FIG. 7A.

FIG. 13A illustrates an enlarged view of the region A shown in FIG. 12Daccording to some embodiments of the present disclosure. As illustrated,the first sub detector cover 1201 may include a first curved piece 1301and two connecting pieces (e.g., a first connecting piece 1302 and asecond connecting piece 1307 (see FIG. 13B)). The two connecting piecesmay be arranged on two ends of the first curved piece 1301,respectively. The first curved piece 1301 and the first connecting piece1302 may be connected via one or more screws. The first connecting piece1302 may have an “L” shape. Similarly, the second sub detector cover1202 may include a second curved piece 1303 and one or more connectingpieces (e.g., a third connecting piece 1304 and a fourth connectingpiece (not shown)). The first connecting piece 1302 may include a firstlong arm 1305. The third connecting piece 1304 may include a second longarm 1306. The first curved piece 1301 and the second curved piece 1303may be the same or different. If the first curved piece 1301 and thesecond curved piece 1303 are the same, the first curved piece 1301 andthe second curved piece 1303 may be used interchangeably. The firstconnecting piece 1302 and the third connecting piece 1304 may be thesame or different. If the first connecting piece 1302 and the thirdconnecting piece 1304 are the same, the first connecting piece 1302 andthe third connecting piece 1304 may be used interchangeably.

The first sub detector cover 1201 and the second sub detector cover 1202may be connected via the connection between the first connecting piece1302 and the third connecting piece 1304. The connection between theconnecting piece 1302 and the connecting piece 1303 may be formed by wayof overlapping, mortise, occlusion, engagement, and the like. In someembodiments, the first connecting piece 1302 and the third connectingpiece 1304 may have complementary structures such that the first subdetector cover 1201 and the second sub detector cover 1202 may beconnected by forming an overlap. For example, the orientations of thefirst long arm 1305 and the second long arm 1306 may be opposite, andthus the connection between the first long arm 1305 and the second longarm 1306 may be formed by way of at least overlapping the first long arm1305 and the second long arm 1306. It should be noted that other regionsrelating to a connection between a first sub detector cover and a secondsub detector cover may be the same as the region A.

FIG. 13B illustrates an enlarged view of the region B shown in FIG. 12Daccording to some embodiments of the present disclosure. As illustrated,a data and power interface 1207 may be connected to the first subdetector cover 1201 and the sixth sub detector cover 1206. The data andpower interface 1207 may be connected to the first sub detector cover1201 via the second connecting piece 1307. The data and power interface1207 may be connected to the sixth sub detector cover 1206 via a fourthconnecting piece 1308. The second connecting piece 1307 and the fourthconnecting piece 1308 may have an “L” shape. It should be noted thatother regions relating to a connection between a data and powerinterface and a sub detector cover may be the same as the region B.

FIG. 14 illustrates a schematic front view of an exemplary scanner 110with a detector cover 320 according to some embodiments of the presentdisclosure. As illustrated, the scanner 110 may include a scanningchannel 1406, a sidewall 1401 of the scanning channel 1406, one or moredetector modules 1403, one or more detector supports 1404, and adetector cover 320. In some embodiments, the detector modules 1403 maybe the same as or different from the detector modules 519 shown in FIG.5B, the detector modules 604 shown in FIG. 6A, the detector modules 612shown in FIG. 6C, and/or the detector modules 711 shown in FIG. 7B. Thedetector cover 320 shown in FIG. 14 may be the same as or different fromthe detector cover 504 shown in FIG. 5A, the detector cover 606 shown inFIG. 6B, the detector cover 618 shown in FIG. 6D, and/or the detectorcover 701 shown in FIG. 7A. The scanning channel 1406 may be the same asor different from the scanning channel 502 shown in FIG. 5A, thescanning channel 518 shown in FIG. 5B, the scanning channel 605 shown inFIG. 6A, the scanning channel 609 shown in FIG. 6B, the scanning channel611 shown in FIG. 6C, and/or the scanning channel 616 shown in FIG. 6D.An object 1402 to be examined may be positioned in the scanning channel1406. Merely by way of example, the scanner 110 is a PET scanner. Thedetector modules 1403 may be configured to detect gamma photons emittedby the object 1402. In some embodiments, the detector module(s) 1403 maybe arranged around the scanning channel 1406 with the support by thedetector support(s) 1404. The detector module(s) 1403 and/or thedetector support(s) 1404 may be arranged in a circle, an ellipse, etc.,around the scanning channel 1406.

The cover plates of the gantry and the detector module(s) 1403 may forma space. The detector cover 320 may be positioned between the coverplates and the detector module(s) 1403. Accordingly, a smaller spacecontaining the detector module(s) 1403 may be formed and isolated fromthe remaining portion of the space. The smaller space may improve thecooling effect of the cooling assembly 113.

FIG. 15 illustrates an exemplary ring assembly 332 according to someembodiments of the present disclosure. As illustrated in FIG. 15, thering assembly 332 may include a first ring 1501 and a second ring 1503.In some embodiments, the first ring 1501 and the first ring 705 shown inFIG. 7B may be the same or different. In some embodiments, the secondring 1503 and the second ring 707 shown in FIG. 7B may be the same ordifferent. The first ring 1501 may include one or more first segments1502. The second ring 1503 may include one or more second segments 1504.The first segments 1502 and/or the second segments 1504 may have acurved shape. In some embodiments, each one of or both of the first ring1501 and the second ring 1503 may further include a flange,respectively. More descriptions regarding the flange may be foundelsewhere in the present disclosure. See, e.g., FIG. 7B and thedescription thereof. In some embodiments, the number of the firstsegments 1502 of the first ring 1501 may be in a range from 5 to 60. Forexample, the number of the first segments 1502 may be 5, 13, or anysuitable number. In some embodiments, the number of the first segments1502 of the first ring 1501 may be 1, i.e., the first ring 1501 may bean integral part. The number of the second segments 1504 of the secondring 1503 may be the same as or different from the number of the firstsegments 1502 of the first ring 1501. In some embodiments, the number ofthe second segments 1504 of the second ring 1503 may be in a range from5 to 60.

In some embodiments, a second segment 1504 may further include a fixingbrim 1505. In some embodiments, the fixing brim 1505 may extend from anouter edge of the second segment 1504. The fixing brim 1505 may be usedto fix the second segment 1504 on a limit plate (e.g., the limit plate515) via one or more screws. In some embodiments, the fixing brim 1505and the second segment 1504 may be an integral piece. In someembodiments, the fixing brim 1505 and the second segment 1504 may beseparate pieces connected together via a screw or welding. In someembodiments, a second segment 1504 may further include a handle 1506.The handle 1506 may be placed on a surface of the second segment 1504away from the detector module(s) 310. The handle 1506 may have a “U”shape, a “T” shape, an “L” shape, any other suitable shape, or the like,or any combination thereof.

FIG. 16 illustrates a schematic configuration of an exemplary scanner110 with a ring according to some embodiments of the present disclosure.Merely by way of example, the scanner 110 is a PET scanner. Asillustrated, an object 1605 (e.g., a patient) laying on a table 1606 maybe positioned inside an imaging region of a scanning channel 1603. Theimaging region may be defined by the scanning channel 1603 and one ormore detector modules 1604. The scanning channel 1603 may be surroundedby the detector modules 1604 and one or more rings, for example, a firstring 1601, a second ring 1602. In some embodiments, the scanning channel1603 and the scanning channel 518 shown in FIG. 5B may be the same ordifferent. In some embodiments, the detector modules 1604 and thedetector modules 711 shown in FIG. 7B may be the same or different. Insome embodiments, the first ring 1601 and the first ring 1501 shown inFIG. 15 may be the same or different. In some embodiments, the secondring 1602 and the second ring 1503 shown in FIG. 15 may be the same ordifferent. In some embodiments, the detector modules 1604 may have afirst side and a second side along an axial direction of the scanningchannel 1603, the first side may be closer to the front face of thescanning channel than the second side. In some embodiments, the firstring 1601 may be located on the first side of the detector modules 1604.In some embodiments, the second ring 1602 may be located on the secondside of detector modules 1604.

Before imaging, a radioactive tracer isotope may be injected into theobject 1605. The tracer isotope may include glucose, protein, nucleicacid, fatty acid labeled with short-lived radionuclides (e.g., F18,C11). Then gamma photons may be emitted from the object 1605. The gammaphotons may be divided into two portions including a first portion and asecond portion. The first portion may be desired gamma photons emittedby a part of the object 1605 in the imaging region. The second portionmay be undesired gamma photons 1607 emitted by another part of theobject 1605 out of the imaging region. The detector modules 1604 maydetect the desired gamma photons and/or the undesired gamma photons1607. The first ring 1601 and the second ring 1602 may block theundesired gamma photons 1607 from being detected by the detector modules1604 such that the undesired gamma photons 1607 detected by the detectormodules 1604 may be reduced and the accuracy of the scanner 110 may beimproved.

FIG. 17A illustrates an enlarged view of the region B shown in FIG. 6Aaccording to some embodiments of the present disclosure. FIG. 17Billustrates an exemplary detector module and an exemplary guide plateaccording to some embodiments of the present disclosure. As illustratedin FIG. 17A, a detector module 604 (including a detector 1710illustrated in FIG. 17B) may be assembled between two adjacent guideplates 602 (e.g., a first guide plate and a second guide plate) or guidepieces 603 (or guide units 508). The detector 1710 may face the scanningchannel to detect signals (e.g., gamma photons). The first guide plateand the second guide plate may be perpendicular or substantiallyperpendicular to the main gantry 601 and distributed along the radialdirection of the scanning channel 605 and fixed via one or more screwsand one or more fixed holes. The fixed holes may be located on the maingantry 601. In some embodiments, the detector module 604 may beconfigured as a cuboid. Accordingly, a first side 1704 and a second side1709 of the detector module 604 may approach the two adjacent guideplates and be substantially parallel to the two adjacent guide plates.

The guide plates 602 may be configured with a guide rail on at least oneside surface. The detector module 604 may be configured with one or moreguide pieces corresponding to the guide rail(s). In some embodiments,the guide rail(s) and the corresponding guide plate(s) may form anintegral part. In some embodiments, the guide rail(s) and thecorresponding guide plate(s) may be separate parts and may be assembledtogether. In some embodiments, the guide rail(s) may be one or moregroove(s) 1703. Correspondingly, the guide piece(s) of the detectormodule 604 may be the bulge(s) 1706 (also referred to as protrusion(s)).In some embodiments, the bulge(s) 1706 (also referred to asprotrusion(s)) of a detector module 604 may be pushed into the groove(s)1703 of the guide rail on a guide plate 602 to assemble the detectormodule 604 with the guide plate 602.

The detector module 604 may be configured with a data interface 1707 anda power interface 1708. The data interface 1707 may be configured totransmit data between the detector module 604 and one or more otherdevices. The power interface 1708 may provide an interface with a powersupplier. In some embodiments, the data interface 1707 and/or the powerinterface 1708 may be configured on an end surface far away from a mainmounting plate of the scanner 110. In some embodiments, the datainterface 1707 and the power interface 1708 may be integrated into adata and power interface.

FIG. 18A illustrates an exemplary detector module 604 and an exemplaryguide unit 508 according to some embodiments of the present disclosure.The guide unit 508 may be a guide plate 1804. One or more guide plates1804 may be arranged along the circumference of the scanning channel605. In some embodiments, the guide plates 1804 may be distributedevenly. A guide plate 1804 may have one or more limit sheets on the leftside and/or right side of the guide plate 1804. The left side and/or theright side may be in a plane perpendicular or substantiallyperpendicular to the axial direction of the scanning channel 605. Thelimit sheets may be located at an end of the guide plate 1804approaching the scanning channel 605. Accordingly, the detector module604 may include one or more limit blocks corresponding to the limitsheets. In some embodiments, a limit sheet may be a hooking brim 1802,and the corresponding limit block may be a flange 1807. The flange 1807of a detector module 604 may be pushed into the recess of the hookingbrim 1802 of a guide plate 1804 to assemble the detector module 604 withthe guide plate 1804. In some embodiments, a limit piece (e.g., thelimit piece 509) may be fixed on the hooking brim 1802 via one or morescrews. The limit piece may limit the movement of the detector module604 in the axial direction of the scanning channel 605.

FIG. 18B illustrates an exemplary detector module 604 and an exemplaryguide unit 508 according to some embodiments of the present disclosure.As illustrated in FIG. 18B, the connection between a detector module 604and a guide unit 508 may be similar to that illustrated in FIG. 18A. Theguide unit 508 may be a guide plate 1804. The connection between thedetector module 604 and the guide unit 508 may be realized via a flangeon the guide plate 1804 and a groove on the detector module 604. In someembodiments, the flange may be located on the guide plate 1804 insteadof on the detector module 604, and the groove may be located on thedetector module 604 instead of on the guide plate 1804.

FIG. 18C illustrates an exemplary detector module 604 and an exemplaryguide unit 508 according to some embodiments of the present disclosure.The guide unit 508 may be a guide column 1803 configured along thecircumference of the scanning channel 605 and perpendicular orsubstantially perpendicular to the main mounting plate. In someembodiments, the guide column 1803 and the main mounting plate may beconfigured as an integral part.

The detector module 604 may include one or more guide holes. In someembodiments, two guide columns 1803 may correspond to one detectormodule 604; accordingly, the detector module 604 may include two guideholes. In some embodiments, one guide column 1803 may correspond to onedetector module 604; accordingly, the detector module 604 may includeone guide hole. The guide columns 1803 may be pushed into correspondingguide holes to assemble the detector module 604 with the guide unit 508.In some embodiments, a screw hole 1806 may be provided at one end (awayfrom the main mounting plate) of a guide column 1803. A limit piece 1801(e.g., the limit piece 509) may be fixed on the guide column 1803 via ascrew inserted into the screw hole(s) 1806. In some embodiments, theguide column 1803 may be a rectangular column, a triangular prism, anoval column, a cylinder, any other suitable column, or the like, or anycombination thereof.

FIG. 19A illustrates a perspective view of an exemplary gantry and anexemplary sliding device 1904 of an imaging device (e.g., a PET device)according to some embodiments of the present disclosure. The gantry(e.g., a PET gantry) may include a gantry base 1901 and a main gantry1902. In some embodiments, the gantry base 1901 and the gantry base 608shown in FIG. 6B may be the same or different. In some embodiments, themain gantry 1902 and the front cover plate 607 shown in FIG. 6B may bethe same or different. An inlet chamber port 1905 and a return chamberport 1906 may be formed on the main gantry 1902. In some embodiments,the inlet chamber port 1905 and the inlet chamber port 620 shown in FIG.6D may be the same or different. In some embodiments, the return chamberport 1906 and the return chamber port 622 shown in FIG. 6D may be thesame or different. One or more detector modules (not shown in FIG. 19A)may be mounted on a detector support (not shown in FIG. 19A). Thedetector support may be assembled on the main gantry 1902. In someembodiments, the detector support may have a circular shape. In someembodiments, the opening of a scanning channel 1950 may be located abovethe gantry base 1901 by a certain distance, as illustrated in FIG. 19A.In some embodiments, a cooling device 1903 in the cooling assembly 113may be supported on the gantry base 1901. In some embodiments, thecooling device 1903 may include one or more components of the coolingassembly 113 including, for example, a refrigerator 410, a compressorchamber 430, etc. The cooling assembly 113 may be used to cool one ormore heat generating components of the imaging device including, forexample, detector modules, electrical components, or the like. Thecooling assembly 113 may cool the imaging device such that thetemperatures of various portions of the imaging device are maintained atacceptable levels and the imaging device functions properly. In someembodiments, a cooling medium cooled by the cooling device 1903 may flowthrough the inlet chamber port 1905 and absorb heat from one or moreheat generating components. Then the heated cooling medium may flowthrough the return chamber port 1906 and return to the cooling device1903 to be cooled. This process may be repeated to cool the heatgenerating components of the imaging device.

As shown in FIG. 19A, the space for accommodating the cooling device1903 on the gantry base 1901 may be relatively small. In someembodiments, it may be inconvenient for an engineer or technician toinstall, maintain, and/or disassemble the cooling device 1903 in such asmall space, and it may reduce the work efficiency of the engineer ortechnician. In the present disclosure, a sliding device 1904 may beprovided underneath the cooling device 1903. In some embodiments, thecooling device 1903 may be mounted on the sliding device 1904 in an openspace outside the gantry (e.g., in a room where the imaging device islocated), a space different from the space for accommodating the coolingdevice 1903 in the gantry. The sliding device 1904 may drive the coolingdevice 1903 to slide onto the gantry base 1901. The cooling device 1903may be aligned with the inlet chamber port 1905 and the return chamberport 1906 to achieve a circulation of the cooling medium in the coolingassembly 113.

FIG. 19B illustrates a perspective view of an exemplary sliding device1904 according to some embodiments of the present disclosure. FIG. 19Cillustrates a front view of an exemplary sliding device 1904 accordingto some embodiments of the present disclosure. FIG. 19D illustrates aside view of an exemplary sliding device 1904 according to someembodiments of the present disclosure. FIG. 19E illustrates a top viewof an exemplary sliding device 1904 according to some embodiments of thepresent disclosure. In some embodiments, the sliding device 1904 mayinclude a supporting plate 1907, a sliding piece 1909, a guide component1912, a baseplate (or baseboard) 1913, and a limit piece 1914.

The supporting plate 1907 may be configured to support the coolingdevice 1903. The supporting plate 1907 may directly contact or be inclose proximity to one or more parts located at the bottom of thecooling device 1903 when the cooling device 1903 is placed on thesupporting plate 1907. In some embodiments, the supporting plate 1907may include one or more holes 1908 (see FIG. 19B, FIG. 19E, and FIG.20A). In some embodiments, the holes 1908 may be through-holes. Theholes 1908 may reduce the weight and/or the cost of the sliding device1904, without reducing the rigidity or strength of the supporting plate1907. In some embodiments, one or more holes may be configured on thebaseplate 1913 to reduce the weight and/or the cost of the slidingdevice 1904.

In some embodiments, the sliding piece 1909 may be located underneaththe supporting plate 1907. In some embodiments, the sliding piece 1909may include a wheel assembly. The wheel assembly may include a wheelbracket 1910 and a wheel 1911 (see FIG. 19C). The wheel bracket 1910 maybe fixedly connected to the supporting plate 1907. The wheel 1911 may bemounted on the wheel bracket 1910. Thus, the supporting plate 1907 maybe connected with the wheel 1911 through the wheel bracket 1910. Thesupporting plate 1907 and the cooling device 1903 located on thesupporting plate 1907 may slide when driven by the wheel 1911. In someembodiments, the sliding piece 1909 may include a sliding block, asliding sheet, a sliding plate, or the like, or any combination thereof.

In some embodiments, the baseplate 1913 may be configured on the gantrybase 1901. For instance, the baseplate 1913 may be fixed on the gantrybase 1901 or be placed directly on the gantry base 1901. In someembodiments, the guide component 1912 supporting the sliding piece 1909may in turn be supported on the baseplate 1913. In some embodiments, theguide component 1912 may include a sliding rail (also referred to assliding guide rail), as shown in FIG. 19B. The sliding rail may includea linear sliding rail, a linear guide rail, or the like. The wheel 1911may slide on the sliding rail, thereby driving the supporting plate 1907and the cooling device 1903 located on the supporting plate 1907 tomove. In some embodiments, the moving direction of the supporting plate1907 may be indicated by the arrow D as illustrated in FIG. 19B. In someembodiments, one or more limit pieces 1914 may be configured on thebaseplate 1913 to limit the position of the cooling device 1903. In someembodiments, the guide component 1912 may include one or more guidegrooves configured on the baseplate 1913, as shown in FIG. 20A and FIG.20B. In some embodiments, the gantry base 1901 may include a guidecomponent configured to coordinate with the sliding piece of the slidingdevice, and the baseplate 1913 may be unnecessary. In some embodiments,the guide component may be mounted or formed on the gantry base 1901.

FIGS. 20A and 20B illustrates a perspective view and a front view ofanother exemplary sliding device 1904 according to some embodiments ofthe present disclosure. Considering that the space for accommodating thecooling device 1903 may be limited, the guide groove(s) (also referredto as the guide component 1912) supported on the baseplate 1913 mayreduce the overall height of the sliding device 1904. The wheel 1911 mayslide on the guide groove(s), thereby driving the supporting plate 1907and the cooling device 1903 located on the supporting plate 1907 tomove. In some embodiments, the moving direction of the supporting plate1907 may be indicated by the arrow D as illustrated in FIG. 20A. In someembodiments, the guide component 1912 may include a guide groove formedon the baseboard 1913. This structure may further reduce the overallheight of the sliding device 1904 so as to facilitate assembly of thecooling device 1903 in a relatively small space. The guide component1912 may guide and limit the sliding path of the sliding piece 1909 suchthat the cooling device 1903 may be accurately slide to a predeterminedposition by the coordination of the guide component 1912 and the slidingpiece 1909, and be aligned with the inlet chamber port 1905 and thereturn chamber port 1906.

The limit piece 1914 may be configured to limit the position of thecooling device 1903 in order to avoid the supporting plate 1907 and thecooling device 1903 located on the supporting plate 1907 to move beyonda certain position along a direction. In some embodiments, the limitpiece 1914 may be fixed on the baseplate 1913. As illustrated in FIG.20B, the height of the limit piece 1914 may be slightly lower than thevertical distance between the supporting plate 1907 and the baseplate1913 defined by the height of the guide component 1912 and the height ofthe sliding piece 1909. In some embodiments, a first screw hole may beconfigured on an end face of the supporting plate 1907. A second screwhole corresponding to the first screw hole may be configured on an endface of the limit piece 1914. The sliding piece 1909 may drive thesupporting plate 1907 and the cooling device 1903 located on thesupporting plate 1907 to move to a predetermined position by thecoordination of the sliding piece 1909 and the guide component 1912.Then the supporting plate 1907 and the limit piece 1914 may be fixedtogether using one or more screws and the screw holes located on the endface of the supporting plate 1907, and thus, the position of the coolingdevice 1903 may be fixed.

In some embodiments, the guide component 1912 and the limit piece 1914may be supported on the baseplate 1913. Accordingly, both of the guidecomponent 1912 and the limit piece 1914 are not directly mounted on thegantry base 1901, and an engineer or technician does not have to installthe guide component 1912 and the limit piece 1914 within the relativelysmall space of the gantry (e.g., a space for accommodating the coolingdevice 1903 in a PET imaging device underneath the scanning channel).The installation of the guide component 1912 and the limit piece 1914onto the baseplate 1913 may be performed in an open space outside thegantry (e.g., in a room where the imaging device is located), a spacedifferent from the space for accommodating the cooling device 1903 in aPET imaging device. Then the baseplate 1913 may be placed on the gantrybase 1901. The cooling device 1903 may slide on the gantry base 1901 bythe coordination of the sliding piece 1909 and the guide component 1912.Thus, the installation and disassembly of the cooling device 1903 may befacilitated. The guide component 1912 and the limit piece 1914configured on the baseplate 1913 may guide the cooling device 1903 toslide accurately to a predetermined position and be fixed in thepredetermined position.

FIG. 21 illustrates a perspective view of an exemplary cooling device1903 supported on an exemplary sliding device 1904 according to someembodiments of the present disclosure. In some embodiments, the slidingdevice 1904 may include the supporting plate 1907, the sliding piece(s)1909, the guide component(s) 1912, the baseplate 1913, and the limitpiece(s) 1914.

To install the cooling device 1903 on a gantry (e.g., a PET imagingdevice), the baseplate 1913 configured with the guide component(s) 1912and the limit piece(s) 1914 may be pushed to a predetermined position onthe gantry base 1901 firstly. The predetermined position may be aposition where the cooling device 1903 may accurately align with theinlet chamber port 1905 and the return chamber port 1906. The coolingdevice 1903 may then be placed on the supporting plate 1907. The coolingdevice 1903 may be placed on the supporting plate 1907 directly or maybe fixed on the supporting plate 1907 using screws. The supporting plate1907 may slide on the guide component 1912 through the sliding piece1909. The cooling device 1903 may slide to a predetermined positionthrough the coordination of the sliding piece 1909 and the guidecomponent 1912. The supporting plate 1907 and the limit piece(s) 1914may be fixed together using screws. Thus, the cooling device 1903 may beinstalled on the gantry base 1901. Releasable fasteners (e.g., buckles)other than screws may be used.

To disassemble the cooling device 1903 from the gantry (e.g., a PETimaging device), the screws (or other releasable fasteners) connectingthe supporting plate 1907 and the limit piece(s) 1914 may be releasedfirstly. The cooling device 1903 supported on the supporting plate 1907may be moved away from the inlet chamber port 1905 and the returnchamber port 1906 by moving the supporting plate 1907. When thesupporting plate 1907 is moved to a certain position, the cooling device1903 may be removed from the supporting plate 1907.

It should be noted that the above description of the sliding device 1904is merely provided for the purposes of illustration, and not intended tolimit the scope of the present disclosure. For persons having ordinaryskills in the art, multiple variations or modifications may be madeunder the teachings of the present disclosure. For example, the limitpiece 1914 and the guide component 1912 may be unnecessary. As anotherexample, the sliding device 1904 may have a self-locking function suchthat the supporting plate 1907 may not arbitrarily move. As stillanother example, the sliding device 1904 may automatically slideactivated by pressing a button on the gantry. However, those variationsand modifications do not depart from the scope of the presentdisclosure.

In some embodiments, a sliding device 1904 may include a supportingplate and a sliding piece. Before installing the cooling device 1903 onthe gantry (e.g., a PET imaging device), the cooling device 1903 may beplaced on the supporting plate firstly. The cooling device 1903 may thenbe pushed on the gantry base 1901 through the sliding device. Thesliding device may have a locking function. If the sliding device slidesto a predetermined position, the supporting plate may stop sliding usingthe locking function of the sliding piece. The predetermined positionmay be a position where the cooling device 1903 may be accuratelyaligned with the inlet chamber port 1905 and the return chamber port1906 configured on the gantry.

In some embodiments, the sliding device 1904 may include a supportingplate, a sliding piece, and a guide component. To install the coolingdevice 1903 on a gantry (e.g., the PET imaging device), the guidecomponent may be mounted on the gantry base 1901 firstly. The coolingdevice 1903 may then be placed on the supporting plate. The coolingdevice 1903 may slide to a predetermined position through thecoordination of the sliding piece and the guide component by causing thesupporting plate of the sliding piece to move. The guide component mayinclude a sliding rail, a guide groove, or the like. The guide groovemay be mounted on the gantry base 1901 or may be formed (e.g., by way ofcarving) in the gantry base 1901.

FIG. 22A illustrates a schematic diagram of an exemplary coolingassembly 113 installed in an exemplary gantry according to someembodiments of the present disclosure. As illustrated in FIG. 22A, a PETimaging device may be used as an example for illustration purposes. ThePET imaging device may include a gantry 2217, a detector cover 2224, oneor more detector modules 2220, a scanning channel 2219, and a coolingassembly 113. The detector modules 2220 may be mounted on the gantry2217 along a peripheral edge of the scanning channel 2219. In someembodiments, the orientation of the detector modules 2220 may beparallel (or substantially parallel) to the axial direction of thescanning channel 2219 and perpendicular (or substantially perpendicular)to a front cover plate of the gantry 2217. In some embodiments, thedetector cover 2224 may shield against an electromagnetic field and/or aradiation ray (e.g., an X-ray radiation of a CT device). In someembodiments, the detector cover 2224 may protect the detector module2220 from electromagnetic interferences. In some embodiments, thecooling assembly 113 may include one or more chilling chambers (e.g.,the chilling chamber 2223) surrounding the detector modules 2220, arefrigerator 2222, an inlet chamber 2209, and a return chamber 2210connecting the chilling chamber(s) and the refrigerator 2222. In someembodiments, the inlet chamber 2209 and the return chamber 2210 may beadjacent to each other. In some embodiments, the inlet chamber 2209 andthe return chamber 2210 may be integrated on a main gantry. In someembodiments, a thermal insulation layer may be arranged on a commonplane (or referred to as a coplane) the inlet chamber 2209 and thereturn chamber 2210 share. The detector module 2220 may be fixed on thecoplane 2227. An air intake 2213 and an air outlet 2214 may be formed onthe coplane 2227. In some embodiments, a thermal insulation layer may beconfigured on the wall of the chilling chamber 2223 in order to reduceundesired heat exchange between the cooling medium in the chillingchamber 2223 and the air outside the cover plate 2226 (e.g., a circularcover plate).

As illustrated in FIG. 22A, an air cooling assembly may be taken as anexample. In some embodiments, the cooling assembly 113 may include anair blower 2207, a heat exchanger 2208 located adjacent to the airblower 2207, an inlet chamber 2209 in fluid communication with the heatexchanger 2208, a return chamber 2210 separated from the inlet chamber2209. The cooling assembly 113 may include a compressor (not shown). Thecompressor may be located in a cooling device (e.g., the cooling device1903) of the cooling assembly 113. In some embodiments, the air blower2207 and the heat exchanger 2208 may be referred to as a refrigerator2222. The inlet chamber 2209 and the return chamber 2210 may also bereferred to as air chambers. The arrows illustrated in the diagram mayindicate the flow direction of a cooling medium (e.g., air).

A detector module 2220 may include one or more crystal units 2204 and acircuit board unit 2221. The circuit board unit 2221 may include aphotomultiplier plate 2205 optically coupled to the crystal units 2204and a front-end electronics circuit board 2206 electrically coupled tothe photomultiplier plate 2205. The photomultiplier plate 2205 may belocated on a side of the crystal unit 2204 facing a connection assembly2216. The photomultiplier plate 2205 may be fixed on both ends of theconnection assembly 2216 along a longitudinal direction of theconnection assembly 2216.

In some embodiments, the detector module 2220 may be fixed to the gantry2217 through the connection assembly 2216. In some embodiments, thedetector module 2220 may include a hollow chamber housing one or moredetector units of the detector module 2220. The hollow chamber mayfurther include a first chamber 2201 and a second chamber 2202. Thefirst chamber 2201 and the second chamber 2202 may be separated by theconnection assembly 2216. The first chamber 2201 may be formed betweenthe photomultiplier plate 2205 and the connection assembly 2216. Thefront-end electronics circuit board 2206 may be located on a back sideof the connection assembly 2216 away from the photomultiplier plate2205. The second chamber 2202 may be formed between the front-endelectronics circuit board 2206 and the connection assembly 2216. In someembodiments, a hole 2203 may be formed on an end of the connectionassembly 2216 along an axial direction of the scanning channel 2219 awayfrom the cooling assembly 113. The cooling medium may flow from thefirst chamber 2201 to the second chamber 2202 (or vice versa) throughthe hole 2203.

The air chamber(s) may be surrounded by one or more baffles. In someembodiments, a baffle 2211 may separate the air chamber from a detectormodule 2220. A clapboard 2212 may be configured in the air chamber andconnected with the baffle 2211. The clapboard 2212 may divide the airchamber into an inlet chamber 2209 and a return chamber 2210. In someembodiments, the inlet chamber 2209 and the return chamber 2210 may beseparated by the clapboard 2212 and/or a common plane 2218 such that theinlet chamber 2209 and the return chamber 2210 are not in fluidcommunication with each other except through the passageway formed bythe first chamber 2201 and the second chamber 2202. In some embodiments,an air intake 2213 and an air outlet 2214 may be formed on the baffle2211. The inlet chamber 2209 may be connected or in fluid communicationwith the first chamber 2201 through the air intake 2213. The returnchamber 2210 may be connected or in fluid communication with the secondchamber 2202 through the air outlet 2214.

The air blower 2207 may drive the cooling medium to spread and/orcirculate in the air chamber(s). The air blower 2207 may regulate theflow rate of the cooling medium. The air blower 2207 may be a fan or ablower. In some embodiments, the flow rate of the cooling medium may beregulated through the variation of the rotation speed of the air blower2207. The heat exchanger 2208 may cool the cooling medium. The heatexchanger 2208 may be a shell and tube heat exchanger, a pillow plateheat exchanger, a fluid heat exchanger, a dynamic scraped surface heatexchanger, a phase-change heat exchanger, or a direct contact heatexchanger, or the like, or any combination thereof. In some embodiments,the heat exchanger 2208 may use a cryogen and/or a refrigerant to coolthe cooling medium. For example, the heat exchanger 2208 may be anevaporator; the evaporator may include one or more conduits with acryogen.

In some embodiments, the detector module 2220 may be a target locationto be cooled. In some embodiments, the cooling medium may be blew to theinlet chamber 2209 by the air blower 2207. The cooling medium may thenreach the first chamber 2201 via the air intake 2213. The cooling mediummay cool down the crystal unit 2204 and the photomultiplier plate 2205in the first chamber 2201. The cooling medium may then flow into thesecond chamber 2202 through the hole 2203 on the connection assembly2216. The cooling medium may cool down the front-end electronics circuitboard 2206 in the second chamber 2202. The cooling medium may flow intothe return chamber 2210 through the air outlet 2214. The cooling mediummay flow back to an air supply chamber housing the air blower 2207through a return chamber port 2215. Then, the cooling medium may becooled by the heat exchanger 2208 for reuse.

In some embodiments, a cover plate 2226 (e.g., a circular cover plate)may be mounted on an end of the detector modules 2220 away from thefront cover plate of the gantry 2217. A chilling chamber 2223 mayinclude a first chamber (e.g., the first chamber 2201) and/or a secondchamber (e.g., the second chamber 2202). The chilling chamber 2223 maysurround the detector module 2220. The chilling chamber 2223 may beformed by a sidewall of the gantry 2217, the cover plate 2226, an innersidewall of the scanning channel 2225, and a back cover plate (notshown). In some embodiments, the chilling chamber 2223 housing thedetector modules 2220 may be configured as a sealed space (also refer toas a confined chamber) in order to improve the cooling efficiency of thecooling assembly 113. In some embodiments, a chilling chamber (e.g., thechilling chamber 2223) may include one or more clapboards configured todivide the chilling chamber into a plurality of sub chambers accordingto the number of the plurality of detector modules. In some embodiments,a sub chamber may include an air intake of an inlet chamber (e.g., theinlet chamber 2209) and an air outlet of a return chamber (e.g., thereturn chamber 2210).

FIG. 22B illustrates a schematic diagram of an exemplary coolingassembly 113 installed in an exemplary main mounting plate according tosome embodiments of the present disclosure. In some embodiments, athermal insulation layer may be configured on a common plane 2218 of aninlet chamber 2209 and a return chamber. The thermal insulation layermay prevent undesired heat exchange between the cooling medium in theinlet chamber 2209 and that in the return chamber 2210. In someembodiments, the temperature difference between the inlet chamber 2209and the return chamber 2210 may be about 5° C.). The thermal insulationlayer may include insulated cotton, cystosepiment, or the like, or anycombination thereof. In some embodiments, a thermal insulation layer maybe configured on a plane other than the common plane of the inletchamber 2209 and the return chamber 2210 in order to reduce undesiredheat absorption of the cooling medium in the inlet chamber 2209. Forexample, a plane other than the common plane between the inlet chamber2209 and the return chamber 2210 may include a thermal insulation layer.As another example, a sidewall of the chilling chamber(s) may include athermal insulation layer.

It should be noted that the above description of the diagrams in FIG.22A and FIG. 22B is merely provided for the purposes of illustration,and not intended to limit the scope of the present disclosure. Forpersons having ordinary skills in the art, multiple variations ormodifications may be made under the teachings of the present disclosure.However, those variations and modifications do not depart from the scopeof the present disclosure. For example, holes or conduits may be formedon a sidewall of the air chamber(s) to connect the air chamber(s) withother cooling medium passage outside the air chamber(s). As anotherexample, the air blower 2207 and the heat exchanger 2208 may be placedin the air chamber(s). As still another example, the air blower 2207 andthe heat exchanger 2208 may be placed outside of the air chamber(s)(e.g., at the bottom of the gantry), and an additional chamber may beformed to connect the air blower 2207 and/or the heat exchanger 2208with the air chamber(s). As a further example, the heat exchanger 2208may be unnecessary; instead, an additional inlet may be configured tointroduce a cooled cooling medium into the air chamber(s), and anadditional outlet may be configured to guide an exhausted cooling mediumto flow out from the air chamber(s). As a still further example, theinlet chamber 2209 and the return chamber 2210 may be separated by theclapboard 2212, the common plane 2218, and/or the baffle 2211. As astill further example, the inlet chamber 2209 and the return cavity 2210may be separated by any other clapboard, plate, and/or baffle (notshown) that may achieve a similar function.

FIG. 23A illustrates an exemplary cooling device 2300 according to someembodiments of the present disclosure. FIG. 23B illustrates an internalstructure of the exemplary cooling device 2300 shown in FIG. 23Aaccording to some embodiments of the present disclosure. The coolingdevice 2300 may include a compressor 2304, a fan 2305, a compressorchamber 2302, and an air supply chamber 2303. The air supply chamber2303 may include an air outlet 2307 of the cooling device 2300corresponding to an inlet chamber port (e.g., the inlet chamber port620, the inlet chamber port 1905). The compressor chamber 2302 mayinclude an air intake 2306 of the cooling device 2300 corresponding to areturn chamber port (e.g., the return chamber port 622, the returnchamber port 1906). In some embodiments, one or more thermal insulationlayers may be installed on the walls of the compressor chamber 2302and/or the air supply chamber 2303.

In some embodiments, the cooling device 2300 and one or more chillingchambers (e.g., the chilling chamber 2223) may be located on the sameside of a gantry. In some embodiments, the cooling device 2300 may belocated below the chilling chamber(s) (see FIG. 22A). In someembodiments, the cooling device 2300 may be located on a left side, aright side, a front side, or a back side of the chilling chambers. Insome embodiments, the cooling device 2300 may be located on top of thechilling chambers. The location of the cooling device 2300 relative tothe chilling chamber(s) is not limited to those exemplified above in thepresent disclosure.

In some embodiments, an inlet chamber (e.g., the inlet chamber 2209) anda return chamber (e.g., the return chamber 2210) may be arrangedadjacent to each other between the cooling device 2300 and the chillingchamber(s). In some embodiments, the inlet chamber and the returnchamber may be integrated on a gantry or a main mounting plate of thegantry. In some embodiments, the inlet chamber port of the inlet chamberin fluid communication with a refrigerator (or cooler) and the returnchamber port of the return chamber in fluid communication with therefrigerator (or cooler) are formed on a coplane facing the detectorassembly 112. In some embodiments, the cooler may include a compressorchamber or an air supply chamber, and a sidewall of the compressorchamber or the air supply chamber may include a thermal insulationlayer. The cooling medium cooled by the cooling device 2300 may flowinto the chilling chamber(s) through the inlet chamber. Then the coolingmedium may absorb heat from one or more detector modules (e.g., thedetector module 2220). The exhausted cooling medium may flow back to thecooling device 2300 through the return chamber and be cooled for reuse.In some embodiments, the inlet chamber and the return chamber may form acoplane (e.g., the coplane 2227). The detector modules, a circular coverplate (e.g., the circular cover plate 2226), and the cooling device 2300may be arranged on the coplane 2227. Thus, the assembly and disassemblyof the gantry may be facilitated.

FIG. 24A illustrates an exemplary PET-CT imaging device 2400 accordingto some embodiments of the present disclosure. The PET-CT imaging device2400 may include a PET imaging device 2401 and a CT imaging device 2405.In some embodiments, the PET imaging device 2401 and the CT imagingdevice 2405 may be arranged side by side in an axial direction of ascanning channel. The PET imaging device 2401 may have a PET scanningchannel. The CT imaging device 2405 may have a CT scanning channel. ThePET scanning channel and the CT scanning channel may be configured foraccommodating an object. In some embodiments, the PET scanning channeland the CT scanning channel may be coaxially arranged.

The PET imaging device 2401 may include a gantry 2402, a detectorassembly configured on the gantry 2402, and a cooling assembly 2404configured to cool the detector assembly. In some embodiments, thedetector assembly may include one or more detector modules 2403 arrangedcircumferentially along the peripheral direction of the PET scanningchannel. The gantry 2402 may support the detector assembly and thecooling assembly 2404 and form the PET scanning channel.

In some embodiments, the cooling assembly 2404 may be distributed on oneor more sides of the detector assembly except for a side of the detectorassembly facing the CT imaging device 2405. For example, as shown inFIG. 24A, the cooling assembly 2404 may be distributed on a back side, aleft side, a right side, an upper side, or a lower side (or anycombination thereof) of the detector assembly and are not distributed ona first side of the detector assembly. The first side may refer to theside of the detector assembly facing the CT imaging device 2405. Theconfiguration of the cooling assembly 2404 may reduce a distance betweena CT scanning plane of the CT imaging device 2405 and a PET scanningplane of the PET imaging device 2401. Thus, the structure of the PET-CTimaging device 2400 may be more compact. A compact structure of thePET-CT imaging device 2400 may shorten a scanning time and reduce aradiation dose to which the object is exposed in a scanning process. Insome embodiments, a table (not shown) may be placed at one end of thePET-CT imaging device 2400 close to the CT imaging device 2405. In ascanning process, the table supporting an object may be moved to the CTscanning plane and then the PET scanning plane. With a compact structureof the PET-CT imaging device 2400, the distance that the table top needsto extend may be reduced, and the deformation of the table top (e.g., atable top with a cantilever structure) due to the weight of the objectand/or the weight of the table top that extends out may be reduced.Thus, the accuracy of scanning may be improved. In some embodiments, thecooling assembly 2404 may have the configuration of the cooling assembly113 illustrated in FIGS. 22A through 23B.

FIG. 24B illustrates an exemplary PET-CT imaging device 2410 accordingto some embodiments of the present disclosure. The PET-CT imaging device2410 may be substantially similar to the PET-CT imaging device 2400. ThePET-CT imaging device 2410 may include a PET imaging device 2411 and aCT imaging device 2415. In some embodiments, a table 2416 may beconfigured on an end of the PET-CT imaging device 2410 close to the CTimaging device 2415. The table 2416 may include a table base 2417 and atable top 2418. The table top 2418 may be slidably connected to thetable base 2417. The table top 2418 may support an object and send theobject to a CT scanning channel of the CT imaging device 2415. A scanregion of the object may be located on a CT scanning plane a. In someembodiments, the CT scanning plane a may pass through a CT tube and amidpoint in an axial direction of the CT scanning channel.

After the CT scanning is completed, the table top 2418 may continue tomove into a PET scanning channel of the PET imaging device 2411 to a PETscanning plane b. The PET scanning plane b may be a transverse planethat passes through the midpoint in an axial direction of the PETscanning channel. The distance between the CT scanning plane a and thePET scanning plane b may affect the PET-CT scanning time and theradiation dose to which an object is exposed.

In some embodiments, the distance between the CT scanning plane a and afirst end face 2413 of the CT imaging device 2415 along the axialdirection of the CT scanning channel may be less than 350 mm. The firstend face 2413 may be close to the table base 2417 and away from the PETimaging device 2411. The distance may also refer to the distance betweenthe CT tube and the first end face 2413 of the CT imaging device 2415.In some embodiments, the distance may be within the range of 300millimeters to 330 millimeters.

The PET imaging device 2411 may have a number of detector rings (e.g.,32 rings, 88 rings, 96 rings, 112 rings, etc.). The PET rings of the PETimaging device 2411 may relate to the number of the detector crystalsdistributed in the axial direction of the PET scanning channel. PETimaging devices configured with different number of detector rings mayhave different axial fields of view (AFOV). As shown in FIG. 24B, thedistance between the CT scanning plane a of the CT imaging device 2415and the PET scanning plane b of the PET imaging device 2411 may bedesignated as D. The length of the detector assembly in the axialdirection along the PET scanning channel may be designated as L. Thedistance between a transverse plane b_(R) of the detector assembly closeto the CT imaging device 2415 and a third end face 2414 of the PETimaging device 2411 along the axial direction of the PET scanningchannel may be designated as d1. The detector assembly may have a firstside (also referred to as the transverse plane b_(R)) and a second sidealong an axial direction of the PET scanning channel. The first side maybe closer to the CT imaging device 2415 than the second side. Thedistance between the first side of the detector assembly and the frontside of the PET imaging device 2411 along the axial direction of thescanning channel may be designated as d1. The third end face 2414 (or afront side) of the PET imaging device 2411 may be close to the CTimaging device 2415. The distance between the CT scanning plane a and asecond end face 2412 of the CT imaging device 2415 in the axialdirection along the CT scanning channel may be designated as d2. Thesecond end face 2412 of the CT imaging device 2415 may be close to thePET imaging device 2411. The distance between the second end face 2412of the CT imaging device 2415 and the third end face 2414 of the PETimaging device 2411 may be designated as d3. In some embodiments, d3 maybe equal to or larger than 0. In some embodiments, the distance Dbetween the PET scanning plane b and the CT scanning plane a may be(L/2+d1+d2+d3). In some embodiments, d1 may be equal to or less than 170millimeters. In some embodiments, d1 may be equal to or less than 150millimeters. In some embodiments, d1 may be equal to or less than 105millimeters or 90 millimeters. Using the structure of the first PET-CTimaging device 2400 described in FIG. 24A, d1 may be effectively reduceddue to its compact structure, and thus, the distance between the PETscanning plane b and the CT scanning plane a may be reducedcorrespondingly. In some embodiments, the CT imaging device 2415 mayhave a first end surface (also referred to as the first end face 2413)and a second end surface (also referred to as the second end face 2412)along an axial direction of the CT scanning channel. The first endsurface is farther from the PET imaging device 2411 than the second endsurface. The CT imaging device 2415 may include an X-ray tube. Thedistance between the X-ray tube and the first end surface of the CTimaging device 2415 along an axial direction of the CT scanning channelmay be equal to or less than 350 millimeters.

In some embodiments, the PET imaging device 2411 may have 88 detectorrings. Accordingly, d1 may be in a range of 160 millimeters to 170millimeters, and D may be in a range of 500 millimeters to 600millimeters. In some embodiments, the PET imaging device 2411 may have96 detector rings. Accordingly, d1 may be in a range of 150 millimetersto 160 millimeters, and D may be in a range of 600 millimeters to 700millimeters. In some embodiments, the PET imaging device 2411 may have112 detector rings. Accordingly, d1 may be in a range of 130 millimetersto 150 millimeters, and D may be in a range of 550 millimeters to 650millimeters.

In some embodiments, an imaging system (e.g., a PET-CT imaging system)may include a first device (e.g., a CT imaging device) and/or a seconddevice (e.g., a PET imaging device). The first device may include afirst scanning channel. The second device may include a second scanningchannel connected to the first scanning channel. The second device mayinclude a heat generating component facing a first side of the seconddevice, wherein the first side of the second device (e.g., the third endface 2414) may face the first device. The heat generating component mayinclude one or more detector modules. The second device may include acooling assembly configured to cool the heat generating component,wherein the cooling assembly may be located at a second side (e.g., aback side, a left side, a right side, an upper side, or a lower side, orany combination thereof) of the second device, and the second side ofthe second device may be different from the first side of the seconddevice.

It should be noted that the above description of the PET-CT imagingdevice 2400 and the PET-CT imaging device 2410 is merely provided forthe purposes of illustration, and not intended to limit the scope of thepresent disclosure. For persons having ordinary skills in the art,multiple variations and modifications may be made under the teachings ofthe present disclosure. In some embodiments, a PET imaging device may becombined with another type of medical imaging device. For example, a PETimaging device may be in combination with an MR device to form a PET/MRdevice. As another example, a PET imaging device may be in combinationwith an X-ray device to form a PET/X-ray device. However, thosevariations and modifications do not depart from the scope of the presentdisclosure.

Having thus described the basic concepts, it may be rather apparent tothose skilled in the art after reading this detailed disclosure that theforegoing detailed disclosure is intended to be presented by way ofexample only and is not limiting. Various alterations, improvements, andmodifications may occur and are intended to those skilled in the art,though not expressly stated herein. These alterations, improvements, andmodifications are intended to be suggested by this disclosure, and arewithin the spirit and scope of the exemplary embodiments of thisdisclosure.

Moreover, certain terminology has been used to describe embodiments ofthe present disclosure. For example, the terms “one embodiment,” “anembodiment,” and/or “some embodiments” mean that a particular feature,structure or characteristic described in connection with the embodimentis included in at least one embodiment of the present disclosure.Therefore, it is emphasized and should be appreciated that two or morereferences to “an embodiment” or “one embodiment” or “an alternativeembodiment” in various portions of this specification are notnecessarily all referring to the same embodiment. Furthermore, theparticular features, structures or characteristics may be combined assuitable in one or more embodiments of the present disclosure.

Further, it will be appreciated by one skilled in the art, aspects ofthe present disclosure may be illustrated and described herein in any ofa number of patentable classes or context including any new and usefulprocess, machine, manufacture, or composition of matter, or any new anduseful improvement thereof. Accordingly, aspects of the presentdisclosure may be implemented entirely hardware, entirely software(including firmware, resident software, micro-code, etc.) or combiningsoftware and hardware implementation that may all generally be referredto herein as a “unit,” “module,” or “system.” Furthermore, aspects ofthe present disclosure may take the form of a computer program productembodied in one or more computer readable media having computer readableprogram code embodied thereon.

A computer readable signal medium may include a propagated data signalwith computer readable program code embodied therein, for example, inbaseband or as part of a carrier wave. Such a propagated signal may takeany of a variety of forms, including electro-magnetic, optical, or thelike, or any suitable combination thereof. A computer readable signalmedium may be any computer readable medium that is not a computerreadable storage medium and that may communicate, propagate, ortransport a program for use by or in connection with an instructionexecution system, apparatus, or device. Program code embodied on acomputer readable signal medium may be transmitted using any appropriatemedium, including wireless, wireline, optical fiber cable, RF, or thelike, or any suitable combination of the foregoing.

Computer program code for carrying out operations for aspects of thepresent disclosure may be written in any combination of one or moreprogramming languages, including an object oriented programming languagesuch as Java, Scala, Smalltalk, Eiffel, JADE, Emerald, C++, C#, VB. NET,Python or the like, conventional procedural programming languages, suchas the “C” programming language, Visual Basic, Fortran 2103, Perl, COBOL2102, PHP, ABAP, dynamic programming languages such as Python, Ruby andGroovy, or other programming languages. The program code may executeentirely on the user's computer, partly on the user's computer, as astand-alone software package, partly on the user's computer and partlyon a remote computer or entirely on the remote computer or server. Inthe latter scenario, the remote computer may be connected to the user'scomputer through any type of network, including a local area network(LAN) or a wide area network (WAN), or the connection may be made to anexternal computer (for example, through the Internet using an InternetService Provider) or in a cloud computing environment or offered as aservice such as a Software as a Service (SaaS).

Furthermore, the recited order of processing elements or sequences, orthe use of numbers, letters, or other designations therefore, is notintended to limit the claimed processes and methods to any order exceptas may be specified in the claims. Although the above disclosurediscusses through various examples what is currently considered to be avariety of useful embodiments of the disclosure, it is to be understoodthat such detail is solely for that purpose, and that the appendedclaims are not limited to the disclosed embodiments, but, on thecontrary, are intended to cover modifications and equivalentarrangements that are within the spirit and scope of the disclosedembodiments. For example, although the implementation of variouscomponents described above may be embodied in a hardware device, it mayalso be implemented as a software only solution, for example, aninstallation on an existing server or mobile device.

Similarly, it should be appreciated that in the foregoing description ofembodiments of the present disclosure, various features are sometimesgrouped together in a single embodiment, figure, or description thereoffor the purpose of streamlining the disclosure aiding in theunderstanding of one or more of the various inventive embodiments. Thismethod of disclosure, however, is not to be interpreted as reflecting anintention that the claimed subject matter requires more features thanare expressly recited in each claim. Rather, inventive embodiments liein less than all features of a single foregoing disclosed embodiment.

In some embodiments, the numbers expressing quantities or propertiesused to describe and claim certain embodiments of the application are tobe understood as being modified in some instances by the term “about,”“approximate,” or “substantially.” For example, “about,” “approximate,”or “substantially” may indicate ±20% variation of the value itdescribes, unless otherwise stated. Accordingly, in some embodiments,the numerical parameters set forth in the written description andattached claims are approximations that may vary depending upon thedesired properties sought to be obtained by a particular embodiment. Insome embodiments, the numerical parameters should be construed in lightof the number of reported significant digits and by applying ordinaryrounding techniques. Notwithstanding that the numerical ranges andparameters setting forth the broad scope of some embodiments of theapplication are approximations, the numerical values set forth in thespecific examples are reported as precisely as practicable.

Each of the patents, patent applications, publications of patentapplications, and other material, such as articles, books,specifications, publications, documents, things, and/or the like,referenced herein is hereby incorporated herein by this reference in itsentirety for all purposes, excepting any prosecution file historyassociated with same, any of same that is inconsistent with or inconflict with the present document, or any of same that may have alimiting affect as to the broadest scope of the claims now or laterassociated with the present document. By way of example, should there beany inconsistency or conflict between the description, definition,and/or the use of a term associated with any of the incorporatedmaterial and that associated with the present document, the description,definition, and/or the use of the term in the present document shallprevail.

In closing, it is to be understood that the embodiments of theapplication disclosed herein are illustrative of the principles of theembodiments of the application. Other modifications that may be employedmay be within the scope of the application. Thus, by way of example, butnot of limitation, alternative configurations of the embodiments of theapplication may be utilized in accordance with the teachings herein.Accordingly, embodiments of the present application are not limited tothat precisely as shown and described.

What is claimed is:
 1. An imaging system, comprising: a first deviceincluding a first scanning channel; and a second device arranged side byside along an axial direction of the first scanning channel, the seconddevice including: a second scanning channel connected to the firstscanning channel; a first side facing the first device; a heatgenerating component; and a cooling assembly configured to cool the heatgenerating component, wherein the heat generating component is closer tothe first side of the second device than at least a portion of thecooling assembly, and the cooling assembly includes: an inlet chamber; areturn chamber; and at least one baffle surrounding at least one of theinlet chamber or the return chamber, the at least one baffle beingconfigured to separate the at least one of the inlet chamber or thereturn chamber from the heat generating component.
 2. The system ofclaim 1, wherein the cooling assembly includes: an air blower configuredto drive cooling air; and wherein the at least one of the inlet chamberor the return chamber is configured to provide a passage for the coolingair, the at least one of the inlet chamber or the return chamber islocated on a second side of the heat generating component other than afirst side of the heat generating component, and the first side of theheat generating component faces the first device.
 3. The system of claim2, wherein the cooling assembly further includes: a heat exchangerconfigured to cool the cooling air, and the inlet chamber is in fluidcommunication with the heat exchanger.
 4. The system of claim 1, whereinthe second device includes a PET device, and the heat generatingcomponent includes a detector assembly.
 5. The system of claim 4,wherein the detector assembly has a first side and a second side alongan axial direction of the first scanning channel or the second thesecond side of the detector assembly, and a first distance along theaxial direction of the first scanning channel or the second scanningchannel between the first side of the detector assembly and the firstside of the PET device facing the first device is equal to or less than170 mm.
 6. The system of claim 5, wherein the first distance is equal toor less than 150 mm.
 7. The system of claim 4, wherein the first deviceincludes a CT device or an X-ray imaging device.
 8. The system of claim7, wherein the CT device has a first end surface and a second endsurface along an axial direction of the first scanning channel or thesecond scanning channel, the first end surface is farther from the PETdevice than the second end surface, the CT device includes an X-raytube, and a second distance between the X-ray tube and the first endsurface of the CT device along an axial direction of the first scanningchannel or the second scanning channel is equal to or less than 350 mm.9. The system of claim 1, wherein the second device further includes oneor more second sides, and the cooling assembly is located on at leastone of the one or more second sides of the second device.
 10. The systemof claim 1, wherein the at least one baffle includes an air intake andan air outlet, the heat generating component includes a first chamberand a second chamber, the inlet chamber is in fluid communication withthe first chamber through the air intake, and the return chamber is influid communication with the second chamber through the air outlet. 11.The system of claim 1, further comprising a clapboard connected to theat least one baffle, and the clapboard being configured to separate theinlet chamber and the return chamber.
 12. The system of claim 1, whereinthe cooling assembly further includes: a cooler; and a chilling chambersurrounding the heat generating component, wherein the inlet chamber isin fluid communication with the chilling chamber, and the return chamberis in fluid communication with the cooler.
 13. The system of claim 12,wherein the inlet chamber and the return chamber have a common plane,and the common plane includes a first thermal insulation layer.
 14. Thesystem of claim 13, wherein an air intake of the inlet chamber in fluidcommunication with the chilling chamber and an air outlet of the returnchamber in fluid communication with the chilling chamber are formed onthe common plane.
 15. The system of claim 13, wherein a plane other thanthe common plane between the inlet chamber and the return chamberincludes a second thermal insulation layer, or a sidewall of thechilling chamber includes a third thermal insulation layer.
 16. Thesystem of claim 12, the cooler includes a compressor chamber or an airsupply chamber, and a sidewall of the compressor chamber or the airsupply chamber includes a fourth thermal insulation layer.
 17. Thesystem of claim 1, wherein: the second device further comprises a gantryassembly, the gantry assembly includes a main gantry and a gantry baseconfigured to support the main gantry, and the inlet chamber and thereturn chamber are integrated on the main gantry.
 18. The system ofclaim 1, wherein the second device further comprises: a gantry assemblyincluding a main gantry and a gantry base configured to support the maingantry, the heat generating component is mounted on the main gantry; anda sliding device configured underneath the cooling assembly tofacilitate mounting of the cooling assembly.
 19. The system of claim 18,wherein the sliding device includes a sliding piece and a supportingplate configured to support the cooling assembly.
 20. The system ofclaim 19, wherein the sliding piece includes a wheel assembly.